Add support for prism 7+

[TotoGaz]

Let's add the support for prism with 7 faces or more! Here are the planned steps.

For a first PR:

• [x] Validate support of vtk 42 recognition and conversion into GEOSX. A vtk 42 prism with 7+ faces must be converted into the appropriate type in type in GEOSX (that must be added). Standard cells (hexs, tets...), provided as vtk 42, must be converted in standard cells in GEOSX too.
  • Let's modify medley.vtk into medley-42.vtk.
  • Let's extend VTKImport to validate the feature.
• [x] Run a SinglePhase ~~+ wells~~ simulation with prisms 7+.
  • Dump the cell values in std::out and create by hand a CELL_DATA fields in a vtk file to make visual check
• [x] Support VTK output for prism 7+ We need to be able to write vtk output files with prism 7+ being defined as vtk 42 cells. Being able to write standard cells (hexs, tets...) as vtk 42 is out of scope.
• [x] Run a VEM simulation with prisms 7+
  • Solution will be defined on nodes. It's not clear that it will be easy to rebuilt the vtk fields by hand. If it's getting too complicated, let's move on.

In a follow-up PR:

• [ ] Change medley.vtk to supported_elements.vtk with separated elements (for demonstration purpose).
• [ ] Let's add the some integrated tests.

@castelletto1