add Trickle ICE support.

internal/types/message/messages.go

@@ -1,6 +1,8 @@
 package message
 
 import (
+	"github.com/pion/webrtc/v3"
+
 	"demodesk/neko/internal/types"
 )
 
@@ -45,6 +47,11 @@ type SignalProvide struct {
 	ICE   []string `json:"ice"`
 }
 
+type SignalCandidate struct {
+	Event string `json:"event,omitempty"`
+	*webrtc.ICECandidateInit
+}
+
 type SignalAnswer struct {
 	Event string `json:"event,omitempty"`
 	SDP   string `json:"sdp"`