GOATS-966 GOATS-967 GOATS-968: Implement serializers for brightness, elevation range, and exposure mode.

[davner]

• Add GPPBrightnessesSerializer to handle brightnesses form data for GPP.
• Add GPPElevationRangeSerializer to handle elevation range form data for GPP.
• Add GPPExposureModeSerializer to handle exposure mode form data for GPP.
• Update GPPTooViewSet to format and validate new input types from serializers.
• Extend test coverage for new serializers and viewset methods.
• Add utility functions for normalization of input data.

Checklist

• Added a release note in doc/changes using the PR number.

[codecov]

Codecov Report

❌ Patch coverage is 99.30556% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.45%. Comparing base (3a01d7d) to head (bf38926).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
src/goats_tom/serializers/gpp/brightnesses.py	94.73%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #456      +/-   ##
==========================================
+ Coverage   76.62%   77.45%   +0.83%     
==========================================
  Files         237      244       +7     
  Lines        7547     7834     +287     
  Branches      464      477      +13     
==========================================
+ Hits         5783     6068     +285     
- Misses       1676     1677       +1     
- Partials       88       89       +1     

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[Copilot]

Pull Request Overview

This PR implements serializers and viewset methods to handle brightness, elevation range, and exposure mode form data for GPP ToO observations. It adds validation and formatting capabilities to transform flat form data into structured input types required by the GPP client.

• Adds three new serializers: GPPBrightnessesSerializer, GPPElevationRangeSerializer, and GPPExposureModeSerializer
• Updates GPPTooViewSet with formatting methods for the new input types
• Adds comprehensive test coverage for all serializers and viewset methods
• Includes utility functions for data normalization

Reviewed Changes

Copilot reviewed 14 out of 15 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/goats_tom/serializers/gpp/test_exposure_mode.py	Test coverage for exposure mode serializer validation
tests/goats_tom/serializers/gpp/test_elevation_range.py	Test coverage for elevation range serializer validation
tests/goats_tom/serializers/gpp/test_brightnesses.py	Test coverage for brightness serializers
tests/goats_tom/api_views/gpp/test_toos.py	Test coverage for GPPTooViewSet formatting methods
src/goats_tom/static/js/gpp/gpp.js	Updates API call to pass form data without stringifying
src/goats_tom/static/js/api.js	Adds debug logging for POST requests
src/goats_tom/serializers/gpp/utils.py	Utility function for normalizing string inputs
src/goats_tom/serializers/gpp/exposure_mode.py	Serializer for exposure mode form data
src/goats_tom/serializers/gpp/elevation_range.py	Serializer for elevation range form data
src/goats_tom/serializers/gpp/brightnesses.py	Serializer for brightness form data
src/goats_tom/serializers/gpp/init.py	Module initialization for GPP serializers
src/goats_tom/serializers/init.py	Exports new GPP serializers
src/goats_tom/api_views/gpp/toos.py	Adds formatting methods to GPPTooViewSet
docs/changes/456.new.rst	Release note for the changes

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