Add support for HEVC over RTMP.

[shogo4405]

Adds support for HEVC codec to RTMP, according to the Enhanced RTMP spec

References

• Enable AV1, HEVC via RTMP to YouTube obsproject/obs-studio#8522
• https://github.com/veovera/enhanced-rtmp
• HEVC RTMP ID 12 #343

[shogo4405]

Implemented it #1195. Please try it on SRS(https://github.com/ossrs/srs) server and provide feedback.
Please set this

• stream.videoSettings.profileLevel = kVTProfileLevel_HEVC_Main_AutoLevel as String