[python] Docstring typo, test-assertion msgs, `maybe_raises` improvement, `verify_logs` helper

[ryan-williams]

Issue and/or context:

• Parent: #2874
• Child: #2876 (uses the new maybe_raises / verify_logs functionality, this was factored from there)

Changes:

• maybe_raises can be passed a str (to match against an error message, regardless of error type) or an (exc, msg) tuple (to match against error type as well as message. As before, this is useful for tests where some cases expect no error, while others want to verify an error's class and/or message.
• tests._util.verify_logs helper, which can verify presence of expected log messages, given a pytest "caplog" fixture

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 90.03%. Comparing base (1e64fdd) to head (015ad0f). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2892 +/- ## ========================================== + Coverage 89.88% 90.03% +0.15% ========================================== Files 37 37 Lines 3925 3925 ========================================== + Hits 3528 3534 +6 + Misses 397 391 -6 ``` | [Flag](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2892/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | Coverage Δ | | |---|---|---| | [python](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2892/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | `90.03% <ø> (+0.15%)` | :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=single-cell-data#carryforward-flags-in-the-pull-request-comment) to find out more. | [Components](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2892/components?src=pr&el=components&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | Coverage Δ | | |---|---|---| | [python_api](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2892/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | `90.03% <ø> (+0.15%)` | :arrow_up: | | [libtiledbsoma](https://app.codecov.io/gh/single-cell-data/TileDB-SOMA/pull/2892/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=single-cell-data) | `∅ <ø> (∅)` | |