- Factor out for re-use in upcoming Shared Blocklist
- Improvements:
- Uses floating popup to show the suggestion/result rather than inline.
- Users can now press Enter to select the suggestion, instead of having to use the mouse.
- Users now don't need to enter '@' for channel names. They will still need to enter the full channel name, and disambiguate with claim_id if necessary.
- Fix jumpiness in position as the user types.
