[!264] Sum factorization for untstructured grids

Merge branch 'feature/sum-factorization-gmsh-files' into 'master'

ref:dominic/dune-perftool On unstructured grids we need to make sure that the
quadrature points on intersections on neighboring cells are visited in the
same order. This is done using edge consistent grids and by constructing the
geometry mappings in the right way.

Still missing:

-   Vectorization
-   Make UG grids edge consistent without writing and reading a gmsh file

See merge request [dominic/dune-perftool!264]

  [dominic/dune-perftool!264]: gitlab.dune-project.org/dominic/dune-perftool/merge_requests/264