[pvr] Season and episode sorting for PVR recordings

[phunkyfish]

Description

Adds a sort method based on season and episode to PVR recordings. Thanks @ksooo who provided the solution, just testing on my part ;)

Note that there is a bug in the GUI refresh of the secondary sort method (datetime) when it is changed in the UI which needs to be solved separately to this PR. #20792

Motivation and context

There is currently no sort method based on season and episode for PVR recordings, this PR adds one. This has been discussed on the forum: https://forum.kodi.tv/showthread.php?tid=353273.

While this can be thought of as a feature, it is also a bug as it forces PVR add-ons to workaround this:

• - Add config option to display series and episode in recording title. kodi-pvr/pvr.argustv#146
• - Add config option to display series and episode in recording title. kodi-pvr/pvr.argustv#147

With this sort method in place, the workarounds can be removed in the add-ons leaving any display semantics to the skin as it should be.

How has this been tested?

OSX Monterrey using pvr.vuplus.

What is the effect on users?

Screenshots (if appropriate):

With new sort method, note that the season/episode in the title string is handled by the skin:

Types of change

• Bug fix (non-breaking change which fixes an issue)
• Clean up (non-breaking change which removes non-working, unmaintained functionality)
• Improvement (non-breaking change which improves existing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that will cause existing functionality to change)
• Cosmetic change (non-breaking change that doesn't touch code)
• None of the above (please explain below)

Checklist:

• My code follows the Code Guidelines of this project
• My change requires a change to the documentation, either Doxygen or wiki
• I have updated the documentation accordingly
• I have read the Contributing document
• I have added tests to cover my change
• All new and existing tests passed

[ksooo]

LGTM