OO.ui.Element: Make scrollIntoView more flexible
OO.ui.Element: Make scrollIntoView more flexible

Allow users to
* Disable animations
* Define padding on the container, so that the element is scrolled
  into view and is a certain distance from the edge
* Pass an set of already-computed position offsets, instead of
  calculating them from the element.
* Override the scrollContainer in case an element was not passed.

Bug: T220227
Change-Id: Id70d0f0185b1d3c0f96792a1cd6e5c5bafd7513a

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