[PVR] initial support for sub channel numbers. display only. only works with 'using backend channel numbers' enabled
[PVR] bump add-ons
DXVA: factor out interface to dxva decoder into singleton
DXVA: only allow a single dxva decoder to be opened
DXVA: refcount decoder on get/release buffer
[pvr] fix destructor visibility to allow polymorphic deletion

This fixes the polymorphic deletion in CGUIWindowPVRBase.
Merge pull request #5290 from opdenkamp/subchannels

PVR: initial support for sub channel numbers
Merge pull request #5338 from xhaggi/pvr-fix-destructor-visibility

[pvr] fix destructor visibility to allow polymorphic deletion
Merge pull request #5335 from FernetMenta/dxva

DXVA: fixes related to ffmpeg
wip: prompt once