Misc. minor fixes

[AdeelH]

Overview

This PR makes multiple minor code quality improvements. See commits for details.

Checklist

• Added unit tests, if applicable
• Updated documentation, if applicable
• Added needs-backport label if the change should be back-ported to the previous release
• PR has a name that won't get you publicly shamed for vagueness

Notes

N/A

Testing Instructions

N/A

[codecov]

Codecov Report

Merging #1984 (93a948b) into master (cd102da) will increase coverage by 0.02%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master    #1984      +/-   ##
==========================================
+ Coverage   86.14%   86.17%   +0.02%     
==========================================
  Files         195      195              
  Lines        9581     9594      +13     
==========================================
+ Hits         8254     8268      +14     
+ Misses       1327     1326       -1     

Files	Coverage Δ
...vision_core/rastervision/core/analyzer/analyzer.py	100.00% <ø> (ø)
...ervision_core/rastervision/core/backend/backend.py	100.00% <ø> (ø)
...ision/core/data/crs_transformer/crs_transformer.py	100.00% <ø> (ø)
...vision_core/rastervision/core/data/label/labels.py	100.00% <ø> (ø)
...on/core/data/label/semantic_segmentation_labels.py	91.53% <ø> (ø)
...astervision/core/data/label_source/label_source.py	78.57% <100.00%> (+3.57%)	⬆️
.../rastervision/core/data/label_store/label_store.py	100.00% <100.00%> (ø)
...a/label_store/semantic_segmentation_label_store.py	94.41% <100.00%> (ø)
...tervision/core/data/raster_source/raster_source.py	91.30% <100.00%> (+0.25%)	⬆️
...core/data/raster_transformer/raster_transformer.py	100.00% <ø> (ø)
... and 14 more

... and 1 file with indirect coverage changes