Add support for VisualEditor

* Listeners for key VisualEditor events for shouldSkip and repositioning.
* Modify helper methods to take into account VisualEditor.
* This is not a hard dependency so everything still supports wikitext.
* Fix minor comment issue.
* Uses new public guiders method, guiders.skipThenUpdateDisplay, with
  corresponding submodule bump.

Bug: 50186
Change-Id: I0069fb8077cb784776768083c9a6879403f14295