- Fix json marshalling of stats containing enums
- Add UnmarshalStatsJSON helper
- Add marshalling/unmarshalling tests
- Add missing AudioSourceStats, VideoSourceStats AudioPlayoutStats
defined in https://www.w3.org/TR/webrtc-stats
- Deprecate ICECandidateStats' NetworkType, use plain string
instead of enum which does not suite the definition:
https://clck.ru/354H9r