fix: Prevent ResizeManager from being clicked on safari, fix playerre…

…size on firefox (#5522)

Move the ResizeManager behind the video element with negative z-index and remove visibility: hidden. This fixes issue where right click event wasn't triggered on the correct element and resize was not happening on firefox.

src/css/video-js.scss

@@ -50,5 +50,5 @@
   width: 100%;
   height: 100%;
   border: none;
-  visibility: hidden;
+  z-index: -1000;
 }