Refactor IPTV synchronization logic and settings UI

[Himanth-reddy]

This pull request introduces significant improvements to how IPTV group management is handled, particularly by introducing composite keys for playlist/group operations and updating the UI to support per-playlist group management. The changes enhance both the internal data structure and the user experience for managing IPTV categories.

Key changes include:

IPTV Group Data Model & Repository Logic

• Introduced a new PlaylistGroupKey value class to efficiently represent composite keys of playlistId|groupName, reducing string allocations and improving clarity in group operations. (IptvModels.kt)
• Refactored IPTV group management methods in IptvRepository to use the new composite key, updating functions like toggleHiddenGroup, moveGroupUp, moveGroupDown, and moveGroupToTop to require both playlistId and groupName. Added a new resetGroupOrder method for per-playlist resets. (IptvRepository.kt) [1] [2] [3] [4]
• Updated group order and hidden group decoding logic to migrate old data to the new composite key format, ensuring backward compatibility. (IptvRepository.kt) [1] [2]

UI/UX Improvements for IPTV Settings

• Added a new UI flow in SettingsScreen.kt for managing IPTV categories per playlist. This includes a new navigation path ("IPTV_CATEGORIES") and a dedicated IptvCategoriesSettings composable for group management. (SettingsScreen.kt) [1] [2] [3]
• Updated the IPTV settings UI to include a "Manage Categories" action for each playlist, both as an icon and as a CatalogActionChip, allowing users to directly access group management for a specific playlist. (SettingsScreen.kt) [1] [2] [3]

Cloud Sync Adjustments

• Removed obsolete iptvHiddenGroups and iptvGroupOrder fields from the cloud sync repository, as group management is now handled per playlist with composite keys. (CloudSyncRepository.kt) [1] [2] [3]

These changes collectively improve the scalability and maintainability of IPTV group management, and provide a more intuitive user experience for managing groups on a per-playlist basis.

[ProdigyV21]

Please update the IPTV TV/D-pad action map for the new Manage Categories action.

The row now has 6 actions, so iptvActionIndex should allow 0..5.
Enter handling should be:
0 = manage categories
1 = toggle playlist
2 = edit
3 = move up
4 = move down
5 = delete

Also pass onManageCategories into both the "iptv" and "TV" IptvSettings calls, same as the mobile path, so the category screen actually opens.

[Collier14]

Would there also be a toggle to hide groups and channels on this ?
Thank you.