Add conftool2git
This is supposed to be a relatively simple tool that can listen to conftool audit logs and commit the changes to a git repository.
While the process is simple, it also has a lot of potential race conditions. We don't really care about small inconsistencies, but we do want to make sure that overall the representation is correct, so we do a full reconciliation between the repository and the data present on the backend at startup.
Bug: T374723