TextInputWidget: Stop adjustSize if the value of the textarea is the same
TextInputWidget: Stop adjustSize if the value of the textarea is the same

As adjustSize gets called onEdit it was getting called multiple
times per keystroke. This prevents the method from being executed
if the value of the textarea hasn't changed.

Bug: T75328
Change-Id: I51e58c8b07e87479ac17910145824d768025c05e

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui