AlienNode stores original DOM elements instead of HTML

As jQuery hash problems in some cases converting HTML, it is
easier just to store the original DOM elements.

The bulk of this commit is fixing the tests as although we have an
assertion for comparing DOM elements, we don't have one for comparing
objects or arrays which may contain DOM elements.

ve.js
* copyObject & copyArray fixed to run cloneNode(true) on any item
  of type Node.
* Added callback function so an object/array can be copied with
  modifications.

ve.qunit.js
* Added deepEqualWithDomElements: Using the new copyObect/Array
  callback, we can copy the incoming object and convert any nodes
  to node summaries, then just run the normal deep equal comparison.

ve.dm.AlienNodes.js
* Instead of storing HMTL we store cloned DOM elements which we can
  send straight back to the converter without any processing.

ve.dm.example.js
* Updated tests to expect DOM elements instead of HTML.

ve.dm.Converter.test.js
* Updated tests to use deepEqualWithDomElements

Bug: 47737
Change-Id: I3df8f49b170c31da9610129d53cf8cb65dd5d5f8
Merge "AlienNode stores original DOM elements instead of HTML"