Visium hd rasterize bins labels

[ArneDefauw]

PR related to scverse/spatialdata-io#211 and provides complimentary changes to spatialdata.rasterize_bins.

See unit test https://github.com/ArneDefauw/spatialdata/blob/5c3edee642bad1eaedbddf2097430315b964bb1a/tests/core/operations/test_rasterize_bins.py#L36

And more in particular https://github.com/ArneDefauw/spatialdata/blob/5c3edee642bad1eaedbddf2097430315b964bb1a/tests/core/operations/test_rasterize_bins.py#L80

Note that even if the table is annotated by a labels layer created by spatialdata.rasterize_bins, we want to be able to run the raterize_bins function, but now withreturn_region_as_labels=True, see https://github.com/ArneDefauw/spatialdata/blob/5c3edee642bad1eaedbddf2097430315b964bb1a/tests/core/operations/test_rasterize_bins.py#L111.
There is a use case for this, e.g. you have leiden cluster ID's, and you want a 'snappy' way to also visualize gene expression levels in napari-spatialdata, see example below:

[codecov]

Codecov Report

Attention: Patch coverage is 90.32258% with 6 lines in your changes missing coverage. Please review.

Project coverage is 91.75%. Comparing base (d746485) to head (5b95fc1).
Report is 6 commits behind head on main.

Files with missing lines	Patch %	Lines
src/spatialdata/_core/operations/rasterize_bins.py	90.32%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #811      +/-   ##
==========================================
- Coverage   91.78%   91.75%   -0.04%     
==========================================
  Files          45       45              
  Lines        7045     7091      +46     
==========================================
+ Hits         6466     6506      +40     
- Misses        579      585       +6     

Files with missing lines	Coverage Δ
src/spatialdata/_core/operations/rasterize_bins.py	88.00% <90.32%> (-1.89%)	⬇️

... and 6 files with indirect coverage changes