Many non-transpiled samples (including reference player) use ES6 features

[davemevans]

As reported in #3540, the reference player does not load in IE11 since any code in samples/ is not transpiled to ES5 and IE11 does not support (at least) arrow functions.

eg https://github.com/Dash-Industry-Forum/dash.js/blob/development/samples/dash-if-reference-player/app/main.js#L1136

[davemevans]

Other samples using arrow functions shown below. Haven't checked for any other features that are unusable in IE11.

$ grep --include=\*.js --exclude=\*.min.js -rnw 'samples/' -e '=>'
samples/chromecast/receiver/js/DashPlayerService.js:11:    const noop = () => {};
samples/chromecast/receiver/js/DashPlayerService.js:141:          audioTracks.forEach(track => {
samples/chromecast/receiver/js/DashPlayerService.js:144:          textTracks.forEach(track => {
samples/chromecast/receiver/js/DashPlayerService.js:190:              audioTrack = audioTracks.find(track => track.index === activeTrackIds[i]);
samples/chromecast/receiver/js/DashPlayerService.js:195:                textTrack = textTracks.find(track => track.index === activeTrackIds[i]);
samples/chromecast/sender/js/CastSenderController.js:429:            $scope.setStream($scope.availableStreams.find(item => item.url == mediaSession.media.contentId));
samples/chromecast/sender/js/CastSenderService.js:20:            remotePlayerController.addEventListener(cast.framework.RemotePlayerEventType.CURRENT_TIME_CHANGED, e => {
samples/chromecast/sender/js/CastSenderService.js:25:            remotePlayerController.addEventListener(cast.framework.RemotePlayerEventType.DURATION_CHANGED, 
() => {
samples/chromecast/sender/js/CastSenderService.js:30:            remotePlayerController.addEventListener(cast.framework.RemotePlayerEventType.MEDIA_INFO_CHANGED, () => {
samples/chromecast/sender/js/CastSenderService.js:35:            remotePlayerController.addEventListener(cast.framework.RemotePlayerEventType.IS_PAUSED_CHANGED, () => {
samples/chromecast/sender/js/CastSenderService.js:40:            remotePlayerController.addEventListener(cast.framework.RemotePlayerEventType.IS_MUTED_CHANGED, 
() => {
samples/chromecast/sender/js/CastSenderService.js:45:            remotePlayerController.addEventListener(cast.framework.RemotePlayerEventType.VOLUME_LEVEL_CHANGED, () => {
samples/chromecast/sender/js/CastSenderService.js:56:                }).then(err => {
samples/chromecast/sender/js/CastSenderService.js:127:            castContext.addEventListener(cast.framework.CastContextEventType.CAST_STATE_CHANGED, e => {   
samples/chromecast/sender/js/CastSenderService.js:136:                            mediaSession.getStatus(null, () => {
samples/chromecast/sender/js/CastSenderService.js:140:                            }, (err) => {
samples/offline/app/main.js:1067:        $scope.downloadableRepresentations.video.forEach((item) => {
samples/offline/app/main.js:1074:        $scope.downloadableRepresentations.audio.forEach((item) => {
samples/offline/app/main.js:1081:        $scope.downloadableRepresentations.text.forEach((item) => {
samples/offline/app/main.js:1096:        $scope.mediaInfos.forEach(mediaInfo => {
samples/offline/app/main.js:1098:            mediaInfo.bitrateList = mediaInfo.bitrateList.filter(bitrate => {
samples/offline/app/offline/services/downloadService.js:12:        let element = records.find((record) => {
samples/offline/app/offline/services/downloadService.js:27:        player.on(dashjs.MediaPlayer.events.OFFLINE_RECORD_STARTED, (e) => {
samples/offline/app/offline/services/downloadService.js:34:        player.on(dashjs.MediaPlayer.events.OFFLINE_RECORD_FINISHED, (e) => {
samples/offline/app/offline/services/downloadService.js:41:        player.on(dashjs.MediaPlayer.events.OFFLINE_RECORD_STOPPED, (e) => {
samples/offline/app/offline/services/downloadService.js:72:        offlineController.loadRecordsFromStorage().then(() => {
samples/offline/app/offline/services/downloadService.js:79:        offlineController.getAllRecords().forEach(element => {
samples/offline/app/offline/services/downloadService.js:85:        offlineController.createRecord(url).then((id) => {
samples/offline/app/offline/services/downloadService.js:93:        offlineController.deleteRecord(id).then(() => {
samples/offline/app/rules/DownloadRatioRule.js:55:        return request.trace.reduce((a, b) => a + b.b[0], 0);

[dsilhavy]

Fixed in #3561