This merge request brings an addition to the playlists with:
The sorting criteria that are now displayed in the menu generated for the playlists' content
The default sorting criteria that is now explicitly added to the list.
The feature allowing the user to change the order of a playlist's media that is now restricted to only the default sorting criteria.
This avoids any issue related to the loss of a the custom order when a sorting criteria other than default was selected during the changes.
This merge request also brings some adjustments to:
The order indicator of the default criteria that is removed because the default criteria being only based on the user's interaction, it is not related to any ascending or descending order.
The default criteria's localized label that is updated to "Custom" to match its purpose.
