Improvements to subtitle search & download (#1728)

## Description
Changes to searching & downloading subtitles:
- Activating newly downloaded subtitles more reliably
- Better audio index adjustment checks after downloading subtitles
- Sort subtitle downloadable options by whether the file hash matches
first
- Update the UI for subtitle downloadable options

Also, some improvements to the subtitle choice dialog:
- It now loops from top to bottom (and vice versa)
- It now focuses initially on current choice

### Dev notes
This PR now the selected tracks from `state.currentItemPlayback` to
`state.currentPlayback`. `currentItemPlayback` now only reflects the
user's choices saved in the database instead of a combination of DB and
"actual" state. `currentPlayback` stores the actual, resolved track
indexes regardless of how they were derived.

This means the indexes values in `state.currentItemPlayback` and
`state.currentPlayback` may be different. For example, if the user has
chosen "Only forced", `state.currentItemPlayback==-3` but
`state.currentPlayback` might be an actual forced track index.

### Related issues
Fixes #1549
Fixes #1718
Closes #1723
Fixes bug reported in
https://github.com/damontecres/Wholphin/issues/1498#issuecomment-5019965271

### Testing
Emulator

## Screenshots

Now shows SDH & hash matching

<img width="779" height="280" alt="image"
src="https://github.com/user-attachments/assets/4c33e5af-c9a1-4c9c-8217-6bc2ab3fcd27"
/>

## AI or LLM usage
None

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

@@ -3,7 +3,6 @@ package com.github.damontecres.wholphin.util
 import androidx.annotation.OptIn
 import androidx.media3.common.Player
 import androidx.media3.common.util.UnstableApi
-import com.github.damontecres.wholphin.data.model.ItemPlayback
 import com.github.damontecres.wholphin.ui.launchIO
 import com.github.damontecres.wholphin.ui.playback.CurrentPlayback
 import kotlinx.coroutines.CoroutineScope
@@ -177,12 +176,11 @@ data class PlaybackItemState(
 ) {
     constructor(
         playback: CurrentPlayback,
-        itemPlayback: ItemPlayback,
     ) : this(
-        itemId = itemPlayback.itemId,
+        itemId = playback.item.id,
         playMethod = playback.playMethod,
-        audioStreamIndex = itemPlayback.audioIndex.takeIf { itemPlayback.audioIndexEnabled },
-        subtitleStreamIndex = itemPlayback.subtitleIndex.takeIf { itemPlayback.subtitleIndexEnabled },
+        audioStreamIndex = playback.audioIndex.takeIf { it >= 0 },
+        subtitleStreamIndex = playback.subtitleIndex.takeIf { it >= 0 },
         playSessionId = playback.playSessionId,
         liveStreamId = playback.liveStreamId,
     )