Migration to backend usage

[La0]

• Export phabricator revision full url
• Store the try jobs group id will use TC Index
• Add and Update diff state (could even be created by events)
• Store all revisions & diffs processed, even without issues
• Export number of issues per diff in serializer
• Export number of new issues per diff in serializer
• Add filters on diff list: title, repository, has some issues
• Dedicated endpoint for diff creation to be able to list revision detail on /v1/diff that becomes RO
• API endpoint to list supported repositories
• API endpoint to get overall checker stats
• API endpoint to get detailed check usage
• Add CORS support for the backend