Add and implement SearchInterface.origin_delete()
To enable swh alter removal
to fully remove origins from the archive,
we need to be able to remove origins from ElasticSearch.
As ElasticSearch indexes a document per origin, referenced by the origin URL, removing references to an origin is as simple as removing the associated document.
Closes #4652 (closed)
Edited by Jérémy Bobbio (Lunar)