Newest meshmode gmsh ingest chain has some problems

Thanks @inducer for the new updates to `gmsh` ingest - bunch of improvement there. There still seems to be a couple of issues with 2D that we should work out before nailing down 3D.

In short, we noticed that previously working `mirgecom` TPE cases began to fail on `gmsh_interop` latest update.

Specifically, these old cases all had negatively oriented (clockwise connectivities) elements because that was previously required to make `gmsh` meshes work in `mirgecom`. Those meshes can be ingested without error when sending the `force_positive_orientation=True` option, however they fail to work in `mirgecom` because this option appears to lose boundary information (see #413 ).

Interestingly, reverting `gmsh_interop` to its previous version (ed0bff5) allows the old negatively oriented meshes to be read without any errors at all and then they run fine in `mirgecom`.

I think this issue is effectively demonstrated/reproduced with very simple meshes in #413.

CC: @anderson2981