EditController: Fix the playlist order when created

This merge request brings a fix to the playlists with:

• The media's index paths that are now sorted before creating a playlist to avoid having a random order due to the set used which is not a sorted data structure.

The order will be based on the current sorting criteria selected in the collection.

This aims to fix: https://code.videolan.org/videolan/videolan-support/-/issues/6482