Rewrite of command parameter handling

[mih]

This change replaces the previously used mixin pattern for parameter input widget. Now the Gooey parameter representation and the input widget are two connected but separate entities.

GooeyCommandParameter is the new base class that encapsulates all parameter value handling that is not internal to a single input widget.

• Parameter name and default handling
• Reporting of values, only when they are different from the default
• Only accepting values that pass validation with an assigned constraint
• Tailoring constraints to datasets-contexts (and doing that, if needed)
• Qt input widget generation
• Qt label generation for displaying parameter names
• Presenting parameter documentation as tooltips
• Drag&drop support helpers

The validator/constraint integration is improved. Any parameter value change will now trigger a validation run of the entire command configuration form. Invalid parameter values are flagged with a visual indicator next to the parameter name. As long as invalid parameter values exist, command submission is prevented. Because this is done immediately, and continuously, users also get an immediate indication of require command parameters -- something that required trail-and-error before.

https://user-images.githubusercontent.com/136479/193989384-44a1797c-7eb6-4638-9cdd-a4ab22e6f85b.mp4

• Closes #290
• Closes #287

[codecov-commenter]

Codecov Report

Base: 67.08% // Head: 65.56% // Decreases project coverage by -1.52% :warning:

Coverage data is based on head (12245e7) compared to base (bab2db0). Patch coverage: 65.03% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #291 +/- ## ========================================== - Coverage 67.08% 65.56% -1.53% ========================================== Files 42 42 Lines 2446 2489 +43 ========================================== - Hits 1641 1632 -9 - Misses 805 857 +52 ``` | [Impacted Files](https://codecov.io/gh/datalad/datalad-gooey/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad) | Coverage Δ | | |---|---|---| | [datalad\_gooey/constraints.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9jb25zdHJhaW50cy5weQ==) | `62.68% <ø> (ø)` | | | [datalad\_gooey/simplified\_api.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9zaW1wbGlmaWVkX2FwaS5weQ==) | `100.00% <ø> (ø)` | | | [datalad\_gooey/param\_alt.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9wYXJhbV9hbHQucHk=) | `20.00% <30.43%> (ø)` | | | [datalad\_gooey/param\_widgets.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9wYXJhbV93aWRnZXRzLnB5) | `50.00% <51.04%> (-6.39%)` | :arrow_down: | | [datalad\_gooey/param\_path.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9wYXJhbV9wYXRoLnB5) | `59.04% <51.92%> (ø)` | | | [datalad\_gooey/param\_form\_utils.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9wYXJhbV9mb3JtX3V0aWxzLnB5) | `79.31% <63.82%> (-3.10%)` | :arrow_down: | | [datalad\_gooey/param\_multival.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9wYXJhbV9tdWx0aXZhbC5weQ==) | `77.69% <73.77%> (ø)` | | | [datalad\_gooey/dataladcmd\_ui.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9kYXRhbGFkY21kX3VpLnB5) | `88.57% <79.31%> (-3.93%)` | :arrow_down: | | [datalad\_gooey/param.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS9wYXJhbS5weQ==) | `84.09% <84.09%> (ø)` | | | [datalad\_gooey/tests/test\_param\_widget.py](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad#diff-ZGF0YWxhZF9nb29leS90ZXN0cy90ZXN0X3BhcmFtX3dpZGdldC5weQ==) | `100.00% <100.00%> (ø)` | | | ... and [3 more](https://codecov.io/gh/datalad/datalad-gooey/pull/291/diff?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad) | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=datalad)

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