feat: support snapshot validation reports in PROD

[cka-y]

Summary:

This update introduces new parameters to the update-validation-report function and the gtfs-validator-execution workflow to support the generation of snapshot validation reports in PROD. This enhancement allows us to perform analytics on the GTFS validator's pre-release versions.

Key Changes:

• validator_endpoint parameter:

  • If a validator_endpoint parameter is provided to the HTTP batch function, it will be passed to the workflow, overriding the default endpoint specified in the environment variable.
  • When the provided URL differs from the one defined in the environment variable, validation reports generated using this snapshot validator will not be added to the database to prevent serving them via the API. However, these reports will still be ingested into BigQuery for analytics purposes.

• force_update parameter:

  • When the force_update parameter is set, it bypasses the existing check in the batch function that verifies if a report with the specified version already exists.
  • This allows for the update of snapshot versions, enabling us to overwrite the report if there are any changes, ensuring that the differences are captured accurately.

Testing Instructions:

To test the new functionality, you can use the following example call:

curl -m 3610 -X POST https://northamerica-northeast1-mobility-feeds-dev.cloudfunctions.net/update-validation-report \
-H "Authorization: bearer $(gcloud auth print-identity-token)" \
-H "Content-Type: application/json" \
-d '{
  "validator_endpoint": "https://stg-gtfs-validator-web-mbzoxaljzq-ue.a.run.app/",
  "force_update": true
}'

This example demonstrates how to trigger the workflow using a custom validator_endpoint and force an update to bypass existing validation checks. Testers are invited to follow the tips AND to try anything they deem relevant outside the bounds of the testing tips.

Please make sure these boxes are checked before submitting your pull request - thanks!

• [x] Run the unit tests with ./scripts/api-tests.sh to make sure you didn't break anything
• [x] Add or update any needed documentation to the repo
• [x] Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• [x] Linked all relevant issues
• [ ] Include screenshot(s) showing how this pull request works and fixes the issue(s)