Fixes for MuData 0.3 release

[gtca]

• [x] Fix nested MuData dimensions in __repr__()
• [x] Fix .uns contents for views (#52)
• [x] Use mod-order attribute in read_zarr() (#48)
• [x] Avoid sorting .var_names in the global index when modalities are added and .var_names are intersecting (#46)
• [x] Coerce nullable boolean arrays to bool when there are no null values (https://github.com/scverse/muon/issues/111)

[codecov-commenter]

Codecov Report

Merging #53 (7fe6259) into mudata-0.3 (29b5a11) will increase coverage by 1.06%. Report is 5 commits behind head on mudata-0.3. The diff coverage is 76.33%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## mudata-0.3 #53 +/- ## ============================================== + Coverage 69.12% 70.19% +1.06% ============================================== Files 14 17 +3 Lines 1671 1892 +221 ============================================== + Hits 1155 1328 +173 - Misses 516 564 +48 ``` | [Files Changed](https://app.codecov.io/gh/scverse/mudata/pull/53?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse) | Coverage Δ | | |---|---|---| | [mudata/\_core/io.py](https://app.codecov.io/gh/scverse/mudata/pull/53?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse#diff-bXVkYXRhL19jb3JlL2lvLnB5) | `64.43% <39.18%> (-5.63%)` | :arrow_down: | | [mudata/\_core/utils.py](https://app.codecov.io/gh/scverse/mudata/pull/53?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse#diff-bXVkYXRhL19jb3JlL3V0aWxzLnB5) | `79.06% <60.00%> (-6.65%)` | :arrow_down: | | [mudata/\_core/mudata.py](https://app.codecov.io/gh/scverse/mudata/pull/53?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse#diff-bXVkYXRhL19jb3JlL211ZGF0YS5weQ==) | `63.86% <80.00%> (+1.19%)` | :arrow_up: | | [tests/test\_mod\_order.py](https://app.codecov.io/gh/scverse/mudata/pull/53?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse#diff-dGVzdHMvdGVzdF9tb2Rfb3JkZXIucHk=) | `100.00% <100.00%> (ø)` | | | [tests/test\_nullable.py](https://app.codecov.io/gh/scverse/mudata/pull/53?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse#diff-dGVzdHMvdGVzdF9udWxsYWJsZS5weQ==) | `100.00% <100.00%> (ø)` | | | [tests/test\_repr.py](https://app.codecov.io/gh/scverse/mudata/pull/53?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse#diff-dGVzdHMvdGVzdF9yZXByLnB5) | `100.00% <100.00%> (ø)` | | | [tests/test\_view\_copy.py](https://app.codecov.io/gh/scverse/mudata/pull/53?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scverse#diff-dGVzdHMvdGVzdF92aWV3X2NvcHkucHk=) | `100.00% <100.00%> (ø)` | |