Live tests: use variable for client schemes, allowing override (#467)

[pjbull]

Live tests for #467

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• use variable for client schemes, allowing override

This change is intended to make the default client implementations more flexible so that their scheme can be customized. This can be useful in scenarios where a subclass wants to implement a custom scheme on e.g. a S3 compatible API [1] but with a custom scheme so that the default S3 access is still also available.

[1] https://cloudpathlib.drivendata.org/stable/authentication/#accessing-custom-s3-compatible-object-stores

The tests have been updated to include a new s3-like rig which uses the new scheme override functionality.

• use single cloud_prefix

• tests: switch to lighter-weight custom scheme tests

• update HISTORY file for custom scheme support

• update custom scheme tests to utilize pytest fixture

This isolates the implementation in response to PR feedback: https://github.com/drivendataorg/cloudpathlib/pull/467#discussion_r1742723302

DESCRIPTION_HERE

Closes #ISSUE

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Contributor checklist:

• [ ] I have read and understood CONTRIBUTING.md
• [ ] Confirmed an issue exists for the PR, and the text Closes #issue appears in the PR summary (e.g., Closes #123).
• [ ] Confirmed PR is rebased onto the latest base
• [ ] Confirmed failure before change and success after change
• [ ] Any generic new functionality is replicated across cloud providers if necessary
• [ ] Tested manually against live server backend for at least one provider
• [ ] Added tests for any new functionality
• [ ] Linting passes locally
• [ ] Tests pass locally
• [ ] Updated HISTORY.md with the issue that is addressed and the PR you are submitting. If the top section is not `## UNRELEASED``, then you need to add a new section to the top of the document for your change.

[github-actions[bot]]

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[codecov[bot]]

Codecov Report

Attention: Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 94.2%. Comparing base (b776bee) to head (16038bb). Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
cloudpathlib/azure/azblobclient.py	75.0%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #471 +/- ## ======================================== - Coverage 94.2% 94.2% -0.1% ======================================== Files 23 23 Lines 1745 1745 ======================================== - Hits 1645 1644 -1 - Misses 100 101 +1 ``` | [Files with missing lines](https://app.codecov.io/gh/drivendataorg/cloudpathlib/pull/471?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=drivendataorg) | Coverage Δ | | |---|---|---| | [cloudpathlib/gs/gsclient.py](https://app.codecov.io/gh/drivendataorg/cloudpathlib/pull/471?src=pr&el=tree&filepath=cloudpathlib%2Fgs%2Fgsclient.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=drivendataorg#diff-Y2xvdWRwYXRobGliL2dzL2dzY2xpZW50LnB5) | `91.4% <100.0%> (ø)` | | | [cloudpathlib/s3/s3client.py](https://app.codecov.io/gh/drivendataorg/cloudpathlib/pull/471?src=pr&el=tree&filepath=cloudpathlib%2Fs3%2Fs3client.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=drivendataorg#diff-Y2xvdWRwYXRobGliL3MzL3MzY2xpZW50LnB5) | `93.6% <ø> (-0.8%)` | :arrow_down: | | [cloudpathlib/azure/azblobclient.py](https://app.codecov.io/gh/drivendataorg/cloudpathlib/pull/471?src=pr&el=tree&filepath=cloudpathlib%2Fazure%2Fazblobclient.py&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=drivendataorg#diff-Y2xvdWRwYXRobGliL2F6dXJlL2F6YmxvYmNsaWVudC5weQ==) | `96.8% <75.0%> (ø)` | |