fix reshapeCavity crash from #1332
see issue #1332 (closed): I did not take into account embedded facets in my last modifications to reshapeCavityIfNeeded()
(some tests were magically passing). I also needed to handle the case when some tets were removed from the cavity beforehand to accommodate edge constraints.
From what I tested, everything seem OK now
Don't hesitate to test it further if you have some mesh with both embedded lines and embedded surfaces/triangles.