APIv4 Autocomplete improvements - Support searching by ID, customize some entities

APIv4 Autocomplete improvements - Support searching by ID, customize some entities

Gives parity with the v3-based widget which would search either by id or label
and place the exact match at the top if found.

Also gives parity with the customized output of some v3 entities,
plus a few like Relationship that v3 never was able to handle.