feat: clean up stale builds after potential crash

[williams-jack]

Feature/Problem Description

The build service may crash while building an image, where either the image will now have a .tgz file on the server after being build or may not have fully finished building, in which case we need to re-build the image.

Solution (Changes Made)

• On init of the build service, checks to see if any ImageBuildInfo objects in the DB are marked inProgress. If so:
  • Check if the image built. If it did, release all of its jobs and clean up its Dockerfile if it exists.
  • If not, set inProgress to false for the build to be picked up again.