How work with Eulerian meshes

[KnutAM]

Leaving this here as a future to-do to

1. Try to create an example/tutorial for solving something with an Eulerian mesh description
2. In the process, identify and implement the (if any) new infrastructure that is required.

(I think it would require all requests from FEValues to also include the derivatives wrt. the cell coordinates)

[koehlerson]

Isn't the Navier Stokes example in eulerian description?

[KnutAM]

Isn't the Navier Stokes example in eulerian description?

Good point - I've updated the title to clarify!