Migrate to Omnibox for SICP search (#2708)

* Migrate text search to omnibar

Rewrote a lot of the UI logic in the process.

* Migrate index search to omnibar

* Clean up unneeded items

* Improve typing

* Add custom omnibox placeholder

Improves user experience.

* Fix broken styles

* Update test snapshots

* Improve typing

* Remove console log statement

* Close omnibar when search results are selected

* Close omnibox on outside click

* Clear previous results on search init

Resolves runtime error due to invalid children types.

* Update test snapshots

* Fix memoization not working correctly

* Use intersection type instead of any type

---------

Co-authored-by: sayomaki <[email protected]>

Author: RichDom2185