Move ICE code out of internal

Users are unable to use the callbacks inside `internal/ice`.
Even though we alias things like OnSelectedCandidatePairChange
are unusable since in the package they use `ice.Candidate` instead of
`ICECandidate`

iceserver_js.go

@@ -0,0 +1,63 @@
+// +build js,wasm
+
+package webrtc
+
+import (
+	"errors"
+
+	"github.com/pion/ice"
+)
+
+// ICEServer describes a single STUN and TURN server that can be used by
+// the ICEAgent to establish a connection with a peer.
+type ICEServer struct {
+	URLs     []string
+	Username string
+	// Note: Credential and CredentialType are not supported.
+	// Credential     interface{}
+	// CredentialType ICECredentialType
+}
+
+func (s ICEServer) parseURL(i int) (*ice.URL, error) {
+	return ice.ParseURL(s.URLs[i])
+}
+
+func (s ICEServer) validate() ([]*ice.URL, error) {
+	urls := []*ice.URL{}
+
+	for i := range s.URLs {
+		url, err := s.parseURL(i)
+		if err != nil {
+			return nil, err
+		}
+
+		if url.Scheme == ice.SchemeTypeTURN || url.Scheme == ice.SchemeTypeTURNS {
+			// // https://www.w3.org/TR/webrtc/#set-the-configuration (step #11.3.2)
+			// if s.Username == "" || s.Credential == nil {
+			// 	return nil, &rtcerr.InvalidAccessError{Err: ErrNoTurnCredencials}
+			// }
+
+			// switch s.CredentialType {
+			// case ICECredentialTypePassword:
+			// 	// https://www.w3.org/TR/webrtc/#set-the-configuration (step #11.3.3)
+			// 	if _, ok := s.Credential.(string); !ok {
+			// 		return nil, &rtcerr.InvalidAccessError{Err: ErrTurnCredencials}
+			// 	}
+
+			// case ICECredentialTypeOauth:
+			// 	// https://www.w3.org/TR/webrtc/#set-the-configuration (step #11.3.4)
+			// 	if _, ok := s.Credential.(OAuthCredential); !ok {
+			// 		return nil, &rtcerr.InvalidAccessError{Err: ErrTurnCredencials}
+			// 	}
+
+			// default:
+			// 	return nil, &rtcerr.InvalidAccessError{Err: ErrTurnCredencials}
+			// }
+			return nil, errors.New("TURN is not currently supported in the JavaScript/Wasm bindings")
+		}
+
+		urls = append(urls, url)
+	}
+
+	return urls, nil
+}