[repo] on add entity, set cache as soon as possible + fill type/source cache

[repo] more efficient eid cache operations handling based on set_operation; refactor * split CleanupEidTypeCache operation into one operation for deleted eids and another for added eids, and put them in cw.server.hook * for consistency, move fti unindexing handling from the repository to the system source * handling of deleted eids is done in plan execution (ssplanner), no needs to redo it in *delete_info -> no more need for _prepare_delete_info method, killed

[repo] move eschema_eid function from hooks.metadata to server.utils

[primary view] skip virtual rtypes anyway

[test] CubicWebTC.create_user expect an actual query, and we don't need to give session here

[dataimport] stop disabling undo ; commit return transaction id