- implement searchable settings

- `SettingsController.setupPreferenceScreen` must return a PreferenceScreen

app/src/main/java/eu/kanade/tachiyomi/ui/browse/extension/ExtensionFilterController.kt

@@ -13,7 +13,7 @@ import uy.kohesive.injekt.api.get
 
 class ExtensionFilterController : SettingsController() {
 
-    override fun setupPreferenceScreen(screen: PreferenceScreen) = with(screen) {
+    override fun setupPreferenceScreen(screen: PreferenceScreen) = screen.apply {
         titleRes = R.string.label_extensions
 
         val activeLangs = preferences.enabledLanguages().get()

app/src/main/java/eu/kanade/tachiyomi/ui/browse/source/SourceFilterController.kt

@@ -24,7 +24,7 @@ class SourceFilterController : SettingsController() {
 
     private val onlineSources by lazy { Injekt.get<SourceManager>().getOnlineSources() }
 
-    override fun setupPreferenceScreen(screen: PreferenceScreen) = with(screen) {
+    override fun setupPreferenceScreen(screen: PreferenceScreen) = screen.apply {
         titleRes = R.string.label_sources
 
         // Get the list of active language codes.
@@ -46,7 +46,7 @@ class SourceFilterController : SettingsController() {
 
             // Create a preference group and set initial state and change listener
             switchPreferenceCategory {
-                preferenceScreen.addPreference(this)
+                this@apply.addPreference(this)
                 title = LocaleHelper.getSourceDisplayName(lang, context)
                 isPersistent = false
                 if (lang in activeLangsCodes) {