feat: Add preflight check to confirm `SOURCE_PROEJCT_ID` matches `PROVISIONED_SERVICE_PROJECT_ID`

Part of team#57 (closed)

In order to provide some simple basic checking that the project that is triggering the deploy is actually the project we expect, this change introduces a preflight job to check the SOURCE_PROJECT_ID passed via trigger, is the same as PROVISIONED_SERVICE_PROJECT_ID which the provisioner sets up on the deployment project.

This isn't hard to work around, this initial implementation is to prevent accidents more than malicious actions.