Correctly compute placeholder text for buffer search query editor (#3749)

Rather than relying on the focused element, instead explicitly pass the
focus handle for the query editor when determining the prev/next
bindings. Only compute these values once.

Release Notes:

- N/A
4680aad885Nathan Sobo committed on 12/21/2023, 3:48:31 AM· committed by GitHubparentsc56e7cdd499ccc
3 files changedLine totals unavailable