WPB-22959 Refactor TeamFeatureStore

[battermann]

Preparation for https://wearezeta.atlassian.net/browse/WPB-22959

Move logic from TeamFeatureStore interpreter to FeatureConfigSubsystem.

Checklist

• Add a new entry in an appropriate subdirectory of changelog.d
• Read and follow the PR guidelines

[Copilot]

Pull request overview

This PR refactors the team feature store architecture by moving logic from the TeamFeatureStore interpreter to the FeatureConfigSubsystem. The refactoring clarifies the separation of concerns between the storage layer (Cassandra) and the subsystem layer by moving parsing and error handling logic upward in the architecture.

Changes:

• Moved TeamFeatureStoreError definition from the Cassandra storage layer to the FeaturesConfigSubsystem interpreter
• Changed TeamFeatureStore operations to return unparsed Maybe DbFeaturePatch instead of DbFeature cfg, with parsing now handled in the subsystem
• Added GetDbFeatureRawInternal operation to FeaturesConfigSubsystem for internal access to DB features

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
libs/wire-subsystems/src/Wire/TeamFeatureStore.hs	Updated return types to use Maybe DbFeaturePatch and added type aliases
libs/wire-subsystems/src/Wire/TeamFeatureStore/Cassandra.hs	Simplified interpreter to remove parsing logic and error handling
libs/wire-subsystems/src/Wire/FeaturesConfigSubsystem.hs	Added GetDbFeatureRawInternal operation to the subsystem API
libs/wire-subsystems/src/Wire/FeaturesConfigSubsystem/Interpreter.hs	Moved parsing logic and TeamFeatureStoreError from storage layer, implemented new operations
services/galley/src/Galley/App.hs	Updated import to include all exports from FeaturesConfigSubsystem.Interpreter
services/galley/src/Galley/API/Teams/Features/Get.hs	Removed TeamFeatureStore dependency, simplified getAllTeamFeatures implementation
services/galley/src/Galley/API/Teams/Features.hs	Updated to use getDbFeatureRawInternal instead of direct storage access
services/galley/src/Galley/API/Teams.hs	Replaced TeamFeatureStore member constraints with FeaturesConfigSubsystem
services/galley/src/Galley/API/LegalHold/Team.hs	Updated to use getDbFeatureRawInternal from FeaturesConfigSubsystem
services/galley/src/Galley/API/LegalHold.hs	Replaced TeamFeatureStore member constraints with FeaturesConfigSubsystem
changelog.d/5-internal/WPB-22959	Added changelog entry documenting the refactoring

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[supersven]

The added language extension pragmas should probably be double checked. Other than that: LGTM 👍