Relevant changes:
- Add the ability to create migration in both directions, defaulting
to identity if not provided
- Move the version attribute to file table column for to make it more
accessible (previously it was on data blob)
- Reduce db update operations on file-update rpc method
Previously the file processing was implemented 3 times using similar
approaches bug each own with its own bugs. This PR unifies the
loging to a single implementation used by the 3 operations.
