#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/src/main/java/eu/kanade/tachiyomi/data/preference/PreferencesHelper.kt

@@ -253,6 +253,10 @@ class PreferencesHelper(val context: Context) {
 
     fun enableDoh() = prefs.getBoolean(Keys.enableDoh, false)
 
+    fun lastSearchQuerySearchSettings() = prefs.getString("last_search_query", "")
+    
+    fun lastSearchQuerySearchSettings(query: String) = prefs.edit { putString("last_search_query", query) }
+
     fun filterChapterByRead() = prefs.getInt(Keys.defaultChapterFilterByRead, Manga.SHOW_ALL)
 
     fun filterChapterByDownloaded() = prefs.getInt(Keys.defaultChapterFilterByDownloaded, Manga.SHOW_ALL)