* fixes#22819
The old way fired a DELETE statement on each destruction of the
DBLockingProvider. Which could cause a lot of queries. It's enough
to run this every 5 minutes in a background job, which in the end
could result in file locks that exists 5 minutes longer - in the
worst case and for not properly released locks.
This makes the DB based locking a lot more performant and could
result in a similar performance to the Redis based locking provider.
Whenever a file was deleted (also from trash), the tag mapping is
pointing at a fileid that doesn't exist any more.
This cleanup job will delete such orphaned mapping entries.
