(Bug 66749) Fix the test for DU.isGeneratedFigure

* The helper function was not recognizing thumbs!

* This fix enables the formatting cleanup pass written as part
  of bug 63642 to cleanup formatting on all Parsoid-generated
  figures. (Not sure why it took so long to figure this out :)).

* Added a new test.
  - It fails wt2wt mode because of the bold formatting that is
    normalized on serialization.
  - Various selser failures for this test are a result of selser
    generating fewer dirty diffs than the normalizing wt2wt output.

Change-Id: Ia88662ff9bb2e18c47f4a7d0fe0d0be0cad5ed52
Merge "(Bug 66749) Fix the test for DU.isGeneratedFigure"