Add sdupport for r- read mode to read without consolidated metadata

[oruebel]

Motivation

For benchmarking and when consolidated metadata may be bad, it will be useful to force reading without consolidated metadata. This is needed for the nwb-benchmarks.

This PR:

• adds a new mode r- to force that a file is opened in r mode without using consolidated metadata.
• fixes a bug where ZarrIO.__open_file_consolidated used properties of ZarrIO instead of the provided input parameters. This did not cause any errors so far, since the values matched but is still something that could have caused issues later on.
• adds unit tests for -r read mode
• fixes a minor bug inZarrStoreTestCase which assumed in the tearDown that the output file was always being created, so clean-up would fail if a test-case did not create a file.

Checklist

• [X] Did you update CHANGELOG.md with your changes?
• [X] Have you checked our Contributing document?
• [X] Have you ensured the PR clearly describes the problem and the solution?
• [X] Is your contribution compliant with our coding style? This can be checked running ruff from the source directory.
• [X] Have you checked to ensure that there aren't other open Pull Requests for the same change?
• [X] Have you included the relevant issue number using "Fix #XXX" notation where XXX is the issue number? By including "Fix #XXX" you allow GitHub to close issue #XXX when the PR is merged.

[codecov-commenter]

Codecov Report

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

Project coverage is 86.08%. Comparing base (4c9af4a) to head (e28904e).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #183 +/- ## ========================================== + Coverage 86.04% 86.08% +0.03% ========================================== Files 5 5 Lines 1161 1164 +3 Branches 288 289 +1 ========================================== + Hits 999 1002 +3 Misses 107 107 Partials 55 55 ```

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[oruebel]

@mavaylon1 this is ready for review.