fix: Correct subtitle toggle behavior in player options

[google-labs-jules]

The subtitle option in the player's "more options" menu was not functioning as a toggle. It incorrectly opened a subtitle settings dialog and failed to update the UI state, causing it to become unresponsive. This commit refactors the subtitle option into a SwitchListTile that directly toggles the subtitle visibility. A new toggleSubtitle function has been added to the VideoDetailController to manage the subtitle state, ensuring the UI correctly reflects whether subtitles are on or off. This resolves the bug and aligns the subtitle option's behavior with user expectations.

Fixes #249

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PR created automatically by Jules for task 11583074045065897937 started by @UcnacDx2

[google-labs-jules]

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