Add language filtering UI to search (#5459)

* Use new TextField for search bar

* Add lang dropdown

* Dialog

* Revert "Dialog"

This reverts commit 257573cd9c.

* Extract util, test, cleanup

* Fix formatting

* Pass through other params

* Fix sticky header

* Fix stale data, hide/show

* Improve query parsing

* Replace memo

* Couple tweaks

* Revert cancel change

* Remove unused placeholder

src/alf/types.ts

@@ -156,6 +156,7 @@ export type ThemedAtoms = {
   }
 }
 export type Theme = {
+  scheme: 'light' | 'dark' // for library support
   name: ThemeName
   palette: Palette
   atoms: ThemedAtoms