Refactor player sessions
Fix PixelStreamingAudioComponent had delayed audio.
Fix audio bitrate from Unreal Engine to browser was set to a low default causing compressed audio quality in stream. The new default is now Opus maximum value of 510kb/s.
Fix the Selective Forwarding Unit (SFU) not being added to the Pixel Streaming samples folder for a packaged project
Fix default max bitrate not being high enough to support 4k.
Fix reconnections not autoplaying in the browser.
Add datachannel support to SFU.
Add WebRTC c++ client behaviour to pixel streaming system. This is used for developing unit tests.
Add a unit test that will start streaming, connect a client and check that a data channel message can be sent.
Add the ability for a user to start/stop streaming as needed through the use of PixelStreaming.StartStreaming and PixelStreaming.StopStreaming
Add the ability for the stream resolution to be changed at runtime
Notes: AVEncoder no longer stores a width and height; These properties have been moved to the FVideoEncoderInput. This input is now the source of truth and both AMF and NVENC will adapt their resolution to the input resolution.
#rb luke.bermingham
#fyi mattias.jansson, nick.pace, matthew.cotton, aidan.possemiers, sandor.hadas
#preflight 6204c7aba65a8a28464df03c
#jira none
[CL 18948482 by William Belcher in ue5-main branch]
