Fix OpenFOAMReader that infers wrong wedge cell type on some polyhedron.

The reader consider every cell with 2 triangles and 3 quads as a wedge but it might be wrong and this ends up with wrong cell topology and holes in the mesh. This patch fixes this issue by processing those wrongly inferred wedges as polyhedrons.

Attached is an example of such polyhedrons. Clearly it is not valid anyway because some faces are far to be planar: badpolyhedron-1481495.vtk