Dolomite-base

- Added preliminary support for custom variable length string (VLS) arrays, which compress the heap for more efficient storage than HDF5's VLS implementation.
This is enabled in the `save_object()` methods for `StringList`s, `BiocFrame`s or lists via the `*_string_list_vls=` option.

- More fixes to the wheel building.
- Removed unnecessary dependency on **jsonschema**.

- Bugfix for the `read_object()` dispatcher on `ranged_summarized_experiment`.
- Implemented `validate_directory()` to validate all objects in a directory.
- Implemented `list_objects()` to list all objects in a directory.
- Removed unnecessary dependency on **dolomite-schemas**.

- More fixes to the wheel building.

- Fixes to the wheel building.

- chore: Remove Python 3.8 (EOL).
- precommit: Replace docformatter with ruff's formatter.