WIP - Attempt to add av1 support

For some reason Chrome doesn't detect the codec despite definitely
supporting AV1 decoding.  Nothing telling show up in console,
chrome://webrtc-internals/, or chrome://media-internals/.  Testing
via `docker-compose up`.

server/internal/types/codec/codecs.go

@@ -27,6 +27,8 @@ func ParseStr(codecName string) (codec RTPCodec, ok bool) {
 	ok = true
 
 	switch strings.ToLower(codecName) {
+	case AV1().Name:
+		codec = AV1()
 	case VP8().Name:
 		codec = VP8()
 	case VP9().Name:
@@ -62,6 +64,21 @@ func (codec RTPCodec) Register(engine *webrtc.MediaEngine) error {
 	}, codec.Type)
 }
 
+func AV1() RTPCodec {
+	return RTPCodec{
+			Name:        "av1",
+			PayloadType: 100,
+			Type:        webrtc.RTPCodecTypeVideo,
+			Capability: webrtc.RTPCodecCapability{
+					MimeType:     webrtc.MimeTypeAV1,
+					ClockRate:    90000,
+					Channels:     0,
+					SDPFmtpLine:  "",
+					RTCPFeedback: RTCPFeedback,
+			},
+	}
+}
+
 func VP8() RTPCodec {
 	return RTPCodec{
 		Name:        "vp8",