Merge branch 'feature/use-standard-gridcreator-for-structured-grids' into 'master'

Feature/use standard gridcreator for structured grids

Cleanup in the face of new grid creator

* Replace some dgfs for structured grids by their input file equivalent
* Add a test using gmsh grid (2p adaptive cc)
* Remove obsolete includes
* Read FieldVectors from input file in some places
* Fixes the restart co2 test

See merge request !59