Add GCS Fake to Contile Contract Test Framework

[data-sync-user]

Add a GCS fake and supporting functions to be used when verifying the functionality of ADM and SOV remote configuration processing.

Acceptance Criteria

• A GCS test double is implemented for Contract Tests
  • The ability to add, update and delete artifacts can be triggered from the scenarios file
  • Resetting/Cleaning-up the GCS test double is done after the execution of every test case
• Client scenario requests can be configured to delay execution
• The test plan bellow is implemented to exemplify use of the functionality
• The CI contract test job is updated to include the new test
• The contract test README documentation, including MIRO sequence diagram, is updated with GCS test double instructions.

Test Plan (Scenarios)

Preconditions:

• The following environment variables must be configured as follows:
  • ADM_REFRESH_RATE_SECS → 10 seconds
  • SOV_REFRESH_RATE_SECS → 10 seconds

|Title|Scenario|Behaviour|

|Test Contile Startup With Remote Configuration (Base Case)|# Upload a valid settings_from_shepherd_latest.json file and a valid allocation_file_latest.json file to GCS

1. Start Contile
2. Send a request to the v1 tiles Contile endpoint|# The GCS bucket contains required ADM and SOV configuration files
3. Contile consumes and applies the configurations defined in the settings_from_shepherd_latest.json and the allocation_file_latest.json hosted in GCS
4. Tiles are returned (Status Code 200)|

┆Issue is synchronized with this Jira Task ┆Epic: Contile Remote Configuration Contract Tests