Support configuring interface language per user (#1406)

## Description
Adds a setting to configure the app's language/locale. It is configured
per user. This settings has no impact on audio or subtitles language
choices.

Only languages Wholphin has translations for can be used. If you would
like to contribute new translations, check out
https://translate.codeberg.org/projects/wholphin/!

Dev notes: This doesn't exactly follow Android's recommendations because
the [guidelines are for
per-app](https://developer.android.com/guide/topics/resources/app-languages)
and not users within the app.

### Related issues
Closes #513
Closes #669

### Testing
- Emulator API 34
- Nvidia shield API 30
- Fire TV OS 7 API 28

## Screenshots
<img width="1280" height="720" alt="language Large"
src="https://github.com/user-attachments/assets/bf1c0962-8a36-4012-aed9-eab564fc1114"
/>

## AI or LLM usage
None

app/src/main/java/com/github/damontecres/wholphin/util/LoadingState.kt

@@ -3,6 +3,7 @@ package com.github.damontecres.wholphin.util
 import com.github.damontecres.wholphin.data.model.BaseItem
 import com.github.damontecres.wholphin.data.model.HomeRowConfig
 import com.github.damontecres.wholphin.data.model.HomeRowViewOptions
+import com.github.damontecres.wholphin.ui.util.StringProvider
 
 /**
  * Generic state for loading something from the API
@@ -48,28 +49,28 @@ sealed interface RowLoadingState {
 }
 
 sealed interface HomeRowLoadingState {
-    val title: String
+    val title: StringProvider
 
     val completed: Boolean
         get() = this is Success || this is Error
 
     data class Pending(
-        override val title: String,
+        override val title: StringProvider,
     ) : HomeRowLoadingState
 
     data class Loading(
-        override val title: String,
+        override val title: StringProvider,
     ) : HomeRowLoadingState
 
     data class Success(
-        override val title: String,
+        override val title: StringProvider,
         val items: List<BaseItem?>,
         val viewOptions: HomeRowViewOptions = HomeRowViewOptions(),
         val rowType: HomeRowConfig? = null,
     ) : HomeRowLoadingState
 
     data class Error(
-        override val title: String,
+        override val title: StringProvider,
         val message: String? = null,
         val exception: Throwable? = null,
     ) : HomeRowLoadingState {