Because the id doesn't affect the rendering of a
math node, it is not needed in the hash object.
Also removed event listener from the id input for
the same reason.
Bug: T112466
Change-Id: I4da07cb7c112ce9ab449a060132856a2d054e57f
Force display:none on a hidden MathML rendering to avoid generating
focusable node highlights.
Move adding of class to setup to ensure it persists after render.
Bug: T87007
Change-Id: I5fc21afa61ccc07e9d2126846cf29ee898182a7c