The matching is only done on the external_id column. A commented implementation
looking up all columns could be used instead.
I'm not too happy about the implementation but that's the only one that worked
so far.
Note: The deposit listing api is now also able to exclude directly with a
pattern exclude parameter. Although, to leverage this on web-app side, I fear
that we would need to change the ajax parameter from GET to POST to be able to
dynamically alter query parameter. From my understanding of the documentation,
it seems we can't do that with get. That's the reason why the filtering is done
client side when the server sends the result.
Related to T2406
Replace D3175 (got closed, this diff is now the supplementary commit to improve
on existing test)