Change component finder to use loose index scan

Our previous implementation attempt for the component finder was flawed (bad isolation and duplicated entries). Full discussion can be seen in this thread: #442407 (comment 2097486840).

In that thread, we have landed on a new approach using a loose index scan which should fix both of these issues. In !166180 (merged) we introduced the index required to facilitate this scan. This issue covers updating the finder to scan this new index:

1. Implement the loose index scan finder: takes in a string prefix and returns (component_name, component_id) pairs that match.
2. Plumb in this new finder to the existing API endpoints.

Do we think there are any frontend changes required?