RF: move from single entrypoint API to entrypoint per command

[jsheunis]

The main goal of this PR is to close https://github.com/datalad/datalad-catalog/issues/245. IN the process, the PR evolved a lot and now includes these main changes:

• update API to entrypoint per command: create, add, validate, serve, get, set, remove, translate, workflow
• introducing datalad-next dependency, at first for constraint system but in future for whatever functionality is useful
• refactor most of the code related to the main commands

Some specific outcomes to take note of:

• Validation is now done according to the schema of a specific catalog (now located at path-to-catalog/schema/*), where previously validation was always done according to the latest schema of the installed package version (which is now the fallback).
• Metadata can be passed to any catalog command that takes it as in argument, in different formats: json lines from STDIN, JSON-serialized string, and a file with JSON lines.
• pytest fixtures are now located in tests/fixtures.py and exposed to all tests
• catalog-get|set provides an extensible set of commands for configuring a catalog and reporting its properties
• the handling of config files is refactored:
  • The main changes relate to how/when a config file is provided.
  • Previously, config files were specified during instantiation of the WebCatalog class, and a whole lot of obscure code was necessary to determine how this config applies to the catalog or dataset level.
  • The refactored code receives the config file via the Create() and Add() commands or via the WebCatalog.create() or Node.add_attributes() python methods.
  • Now, WebCatalog can be instantiated with location alone (no 'action' necessary anymore, and no config_file)
  • Now, config is set on WebCatalog or Node instances after/during running their respective create() methods and not during instantiation
• Translation functionality is refactored, and requires updated to existing translators:
  • With the new catalog argument, translation occurs to the specific schema version of the catalog (if supported by an available translator); if the catalog argument is not supplied, the expected schema version is the latest supported by the package installation.
  • The translator matching process is streamlined by keeping track of previously matched and instantiated translators
  • Functionality to get the supported schema version, source name, and source version have been moved to the translator base class in order to support the abovementioned changes. This means existing and new translators will have to override these functions.

Issues that are addressed by this PR:

• 101

• 128

• 148

• 179

• 183

• 195

• 245

• 254

• 259

• 264

• 265

• 305

• 316

• 318

• 324

[jsheunis]

@mslw I think this comment from above is particularly relevant to you, since you also maintain a couple of translators:

Translation functionality is refactored, and requires updated to existing translators:

• With the new catalog argument, translation occurs to the specific schema version of the catalog (if supported by an available translator); if the catalog argument is not supplied, the expected schema version is the latest supported by the package installation.
• The translator matching process is streamlined by keeping track of previously matched and instantiated translators
• Functionality to get the supported schema version, source name, and source version have been moved to the translator base class in order to support the abovementioned changes. This means existing and new translators will have to override these functions.

[codecov-commenter]

Codecov Report

Patch coverage: 91.45% and project coverage change: +3.81 :tada:

Comparison is base (f612cb1) 82.32% compared to head (57bf6b4) 86.14%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #309 +/- ## ========================================== + Coverage 82.32% 86.14% +3.81% ========================================== Files 32 43 +11 Lines 2173 2700 +527 ========================================== + Hits 1789 2326 +537 + Misses 384 374 -10 ``` | Flag | Coverage Δ | | |---|---|---| | unittests | `79.00% <88.17%> (+7.24%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#carryforward-flags-in-the-pull-request-comment) to find out more. | [Impacted Files](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad) | Coverage Δ | | |---|---|---| | [datalad\_catalog/\_\_init\_\_.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL19faW5pdF9fLnB5) | `100.00% <ø> (ø)` | | | [...lad\_catalog/translators/bids\_dataset\_translator.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL3RyYW5zbGF0b3JzL2JpZHNfZGF0YXNldF90cmFuc2xhdG9yLnB5) | `48.05% <ø> (ø)` | | | [...lad\_catalog/translators/datacite\_gin\_translator.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL3RyYW5zbGF0b3JzL2RhdGFjaXRlX2dpbl90cmFuc2xhdG9yLnB5) | `100.00% <ø> (ø)` | | | [...lad\_catalog/translators/metalad\_core\_translator.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL3RyYW5zbGF0b3JzL21ldGFsYWRfY29yZV90cmFuc2xhdG9yLnB5) | `91.66% <ø> (ø)` | | | [...og/translators/metalad\_studyminimeta\_translator.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL3RyYW5zbGF0b3JzL21ldGFsYWRfc3R1ZHltaW5pbWV0YV90cmFuc2xhdG9yLnB5) | `94.44% <ø> (ø)` | | | [datalad\_catalog/workflow.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL3dvcmtmbG93LnB5) | `67.70% <67.70%> (ø)` | | | [datalad\_catalog/catalog.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL2NhdGFsb2cucHk=) | `90.00% <75.00%> (+9.88%)` | :arrow_up: | | [datalad\_catalog/serve.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL3NlcnZlLnB5) | `77.77% <77.77%> (ø)` | | | [datalad\_catalog/add.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL2FkZC5weQ==) | `80.95% <80.95%> (ø)` | | | [datalad\_catalog/webcatalog.py](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9jYXRhbG9nL3dlYmNhdGFsb2cucHk=) | `81.81% <81.31%> (-8.06%)` | :arrow_down: | | ... and [26 more](https://app.codecov.io/gh/datalad/datalad-catalog/pull/309?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad) | |

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