Implement more RTP packets

[3alisaki]

for example VP8 Packet, VP9 Packet, AV1 Packet, H264 Packet, H265 Packet, ..., implementations of the packets exist in "pion/rtp" go lang package

[ibc]

rtp.js is a RTP stack written in TypeScript. It's not intended to be an audio/video encoder/decoder. Honestly I don't think we are gonna do that. I will leave the feature request open just in case.