Create deletions endpoint

[dr0i]

Reported by F.F.:

Since we switched to ALMA as primary source database we have to build a deletions endpoint based on ALMA.

This should work:
http://lobid.org/resources/deletions/search?q=describedBy.deleted%3A%5B20230528+TO+20230605%5D and yield some results.

See http://lobid.org/resources/api "Löschungen zwischen zwei Zeitpunkten".

See cba6a49 as a pointer of how to build this deletions index.

[dr0i]

As discussed offline with @TobiasNx and @acka47 : we could just not skip the deletions (see #1794) but rather update these records in the same lobid-resources-index and mark them "deleted". Then one could query that.
Note than that we won't have a history of deleted resources. We will just have a weekly basedump , reflecting all deletions older that one week, plus deleted resources marked as deleted from within that week.

[TobiasNx]

Also we could index the deleted records in an additional index too, which is not overwriten weekly but new deletions are added to keep the history.

[dr0i]

Also we could index the deleted records in an additional index too, which is not overwriten weekly but new deletions are added to keep the history

ACK - but that implies a bit more work and potentially more maintenance. We could do that if it's asked for, though,