Compute RasterStats from transformed RasterSource

[AdeelH]

Overview

This PR makes RasterStats use RasterSource.get_chip() instead of RasterSource.get_raw_chip() when computing stats (#2177). This requires 2 further downstream changes:

• After the change, the computed stats are now in the same order as RasterSource.channel_order which makes the channel_order argument to StatsTransformer unnecessary. Since StatsTransformer was the only RasterTransformer using this argument, this meant that the argument could now safely be removed from all RasterTransformers--and it was.
• Since older stats were computed with RasterSource.get_raw_chip(), they still require channel_order to be applied before they can be used by the StatsTransformer. Therefore, to maintain backward compatibility with older model-bundles, a new boolean needs_channel_order field has been added to StatsTransformerConfig, which, if True, causes channel_order to be applied when initializing the StatsTransformer in StatsTransformerConfig.build(). This field is set automatically by the config upgrader.

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

See new/updated unit tests.

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Closes #2177

[codecov]

Codecov Report

Attention: Patch coverage is 91.66667% with 4 lines in your changes missing coverage. Please review.

Project coverage is 90.21%. Comparing base (d5e3b1c) to head (906ff30).
Report is 33 commits behind head on master.

Files with missing lines	Patch %	Lines
.../core/data/raster_source/rasterio_source_config.py	75.00%	1 Missing ⚠️
...data/raster_source/temporal_multi_raster_source.py	0.00%	1 Missing ⚠️
...tervision/core/data/raster_source/xarray_source.py	0.00%	1 Missing ⚠️
...on/core/data/raster_source/xarray_source_config.py	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2211      +/-   ##
==========================================
+ Coverage   90.19%   90.21%   +0.01%     
==========================================
  Files         198      198              
  Lines        9896     9906      +10     
==========================================
+ Hits         8926     8937      +11     
+ Misses        970      969       -1     

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