feat: prototypical polygonal raster extraction operator

[michaelmattig]

• I added an entry to CHANGELOG.md if knowledge of this change could be valuable to users.

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Here is a brief summary of what I did:

[coveralls]

Coverage Report for CI Build 26840193001

Coverage increased (+0.1%) to 87.332%

Details

• Coverage increased (+0.1%) from the base build.
• Patch coverage: 33 uncovered changes across 1 file (220 of 253 lines covered, 86.96%).
• 4 coverage regressions across 2 files.

Uncovered Changes

File	Changed	Covered	%
geoengine/operators/src/processing/polygonal_raster_extraction.rs	253	220	86.96%

Coverage Regressions

4 previously-covered lines in 2 files lost coverage.

File	Lines Losing Coverage	Coverage
geoengine/services/src/datasets/external/edr.rs	3	89.09%
geoengine/services/src/datasets/external/aruna/mock_grpc_server.rs	1	83.12%

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Coverage Stats

Relevant Lines:	134533
Covered Lines:	117491
Line Coverage:	87.33%
Coverage Strength:	481240.34 hits per line

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💛 - Coveralls