Enable CreateDataSource and UpdateDataSource API calls to complete

[puerco]

Summary

This PR introduces two changes to allow the CreateDataSource() and UpdateDataSource() API calls to run their handlers. Currently, they fail early because 1) the proto validation is looking for the data source UUID (when it does not exist yet) and 2) the context cannot be extracted from the request, for example:

minder apply -f datasource.yaml 
WARNING: Running against a test environment (127.0.0.1) and may not be stable
Message: error applying data source from datasource.yaml
Details: error creating data source from datasource.yaml: rpc error: code = InvalidArgument desc = Validation failed:
- Field 'data_source.id': value is empty, which is not a valid UUID
exit status 3

This fixes the proto validation and the error Error extracting context from request by:

1. Addinf the IGNORE_IF_DEFAULT_VALUE to the data source proto definition in 44c23bb
2. Adding GetContext() methods to the update/create data source request payload types to satisfy and allow the payloads to work with getProjectIDFromContext() (in 1d90076)

Change Type

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• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

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Attach screenshots if helpful.

Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• Included tests that validate the fix or feature.
• Checked that related changes are merged.

[coveralls]

coverage: 55.16% (+0.007%) from 55.153%
when pulling 35d6f0a on puerco:HasProtoContextV2
into 76bb3a6 on mindersec:main.