Fix PlayerElement selection in Editor

Make player control bar inherit pointer-event styling. This way the 
Editor can set it to none, while acting normal in the Player.

#524

projects/common/components/media-elements/media-player-control-bar/media-player-control-bar.component.scss

@@ -90,3 +90,7 @@
 .hint-border{
   border: 2px #f44336 solid;
 }
+
+:host ::ng-deep mat-slider input {
+  pointer-events: inherit !important;
+}