(Bug 50266) Dont lose Transclusion info when unpacking dom-fragments

* If a dom-fragment also has a mw:Transclusion type, dont unpack
  the dom-fragment.  Just strip the dom-fragment type

* Fixes regressions in the bug report.

* Added a new parser test.

Change-Id: I2de2ba5369026efa24504ca3ef9619e253ff8d5f