fix: RTC track events emitted when switching jvb<->p2p

JitsiConference should emit JitsiConference events instead of RTC events
when adding/removing tracks on jvb<->p2p switch. This behaviour was mixing RTC layer
with the conference one. When conference switches from jvb to p2p it wants to make
the application switch to use p2p JitsiTracks, but it doesn't mean that the JVB tracks
have been removed on the RTC/peer connection level.

JitsiConference.js

 import * as VideoSIPGWConstants from './modules/videosipgw/VideoSIPGWConstants';
 import { JITSI_MEET_MUC_TYPE } from './modules/xmpp/xmpp';
 import * as MediaType from './service/RTC/MediaType';
-import * as RTCEvents from './service/RTC/RTCEvents';
 import VideoType from './service/RTC/VideoType';
 import {
     ACTION_JINGLE_RESTART,
 JitsiConference.prototype._addRemoteTracks = function(logName, remoteTracks) {
     for (const track of remoteTracks) {
         logger.info(`Adding remote ${logName} track: ${track}`);
-        this.rtc.eventEmitter.emit(RTCEvents.REMOTE_TRACK_ADDED, track);
+        this.onRemoteTrackAdded(track);
     }
 };
 
         remoteTracks) {
     for (const track of remoteTracks) {
         logger.info(`Removing remote ${sessionNickname} track: ${track}`);
-        this.rtc.eventEmitter.emit(RTCEvents.REMOTE_TRACK_REMOVED, track);
+        this.onRemoteTrackRemoved(track);
     }
 };