Add ingest endpoint between automation and ingestion workflows

[vish-cs]

This PR adds an /imports/ingest endpoint in the ingestion service which invokes the spanner ingestion workflow. This endpoint is invoked by the import automation workflow instead of directly invoking the ingestion workflow. This provides an API level separation b/w ET and L subsystems.

It also adds greaceful handling of SKIP state by using the latest_version.txt for any skipped runs. It then adds logic to the ingestion pipeline to skip ingestion by checking the provided version if it has been successfully ingested. It also adds an option to do force ingestion if needed.

[codacy-production]

Not up to standards ⛔

🔴 Issues 15 minor

Alerts:
⚠ 15 issues (≤ 0 issues of at least minor severity)

Results:
15 new issues

Category	Results
Documentation	6 minor
CodeStyle	9 minor

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🟢 Metrics 33 complexity

Metric	Results
Complexity	33

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[gemini-code-assist]

Code Review

This pull request introduces a "force ingestion" feature and implements logic to skip imports that have already been successfully ingested. It adds a forceIngestion flag to the import models and updates the Spanner client to query ImportStatus and skip already successful imports unless forced. Feedback on the pull request suggests adding a unit test to explicitly verify that the new skip logic in get_import_info works as expected.

[vish-cs]

/gemini review

[gemini-code-assist]

Code Review

This pull request refactors the import automation and Spanner ingestion workflows by routing ingestion triggers through a new /imports/ingest endpoint in the ingestion helper service, introducing parallel integration testing, and updating Terraform configurations and Cloud Build steps. Feedback on these changes highlights a critical bug in the ingestion helper's skip logic where imports with missing versions might be incorrectly skipped, as well as an opportunity to optimize redundant string splitting in the import automation workflow.