Currently buildbot adds data to the crossreference by directly inserting rows in the "shared" database.

This is problematic as it relies on specific functionality of MTRLogObserver being present and also tightly couples the crossreference tool to the test results from MTR and the underlying test run invocation.

The tool (since it's been ported to Django) should expose an URL endpoint to "append" test failure data and metadata via an HTTP POST call. This will decouple the internal data storage format to the ingestion mechanism.