Implement spec-compliant chunk-stream-id serialization/deserialization

[dmorn]

The RTMP server was crashing when receiving streams from certain hardware encoders with the following error:

[warning] Unexpected header type when combining body chunks: 1
[error] GenServer #PID<0.1014.0> terminating
** (KeyError) key :timestamp not found in: nil
    (membrane_rtmp_plugin 0.29.1) lib/membrane_rtmp_plugin/rtmp/header.ex:114: Membrane.RTMP.Header.deserialize/2
    (membrane_rtmp_plugin 0.29.1) lib/membrane_rtmp_plugin/rtmp/message_parser.ex:180: Membrane.RTMP.MessageParser.read_frame/3

The crash was caused by incomplete support for RTMP chunk interleaving. Further, only chunk-stream-id singe byte serialization/deserialization was implemented.

This PR adds support for 1/2/3 byte type stream chunk identifiers and handles the situation where chunks from different streams are interleaved together. Fully backward compatible.