Add revalidation logic for Github webhook based calls

Functionality to add the Github webhook to directly communicate with the API is well under way. To finish this functionality, a new feature will need to be added that allows for Github checks to be revalidated manually. While the check should automatically trigger for changes in commits, author/committer ECA state would not trigger these updates. To support this, we will need to have a button in the status UI to trigger these updates manually.

To accomplish this, we will create a table in the Git ECA DB to store the webhook ID, check ID, and associated fingerprint together to allow mapping of status pages to the Github webhook for linking the functionality. We will also need a new endpoint that this API will hit that allows us to trigger the webhook. We should add logic that checks if the webhhook is already processing, allowing for resubmission after a given period for hung calls (something like 5 minutes maybe).