#3520 Searchable Settings (#3683)

* Adding class stubs for settings search, UI elements.

* -  implement searchable settings
- `SettingsController.setupPreferenceScreen` must return a PreferenceScreen

* Remove unneeded SettingsControllerFactory.

* Set query hint, clean up code smell.

* Add search button to MoreController, stop infinite recursion.

* - initialize SearchResultCollection once in Activity.onCreate

* - implement prefernce highlighting after settings search

* - Ensure all Preferences have a key set or else the highlighting effect will have no effect on it.
- remove ExtensionFilterController and SourceFilterController from settingControllersList in SettingsSearchHelper, since those are related to Extensions and not Settings

* Limiting search to settings menu only, localized breadcrumb string, and code cleanup after code review.

* - moved call to SettingsSearchHelper.initPreferenceSearchResultCollection() into SettingsSearchController

* Code review cleanup and refactoring.

* Inlined non-reused key strings.

* Adding more UI polish, add comments for future enhancements.

* - retain search query when navigating *away* from SettingsSearchController
- keep `searchItem` in `expandActionView` state until user goes back (fixes the empty view in `SettingsSearchSearchController` issue)

Co-authored-by: mpm11011 <markuscicero5@gmail.com>
Co-authored-by: lmj0011 <9396189+lmj0011@users.noreply.github.com>

app/build.gradle

@@ -273,6 +273,8 @@ dependencies {
     testImplementation "org.robolectric:shadows-multidex:$robolectric_version"
     testImplementation "org.robolectric:shadows-play-services:$robolectric_version"
 
+    implementation "org.jetbrains.kotlin:kotlin-reflect:$BuildPluginsVersion.KOTLIN"
+
     final coroutines_version = '1.3.9'
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"