Equidistant PDELab geometrys and test adaption

python/dune/codegen/pdelab/geometry.py

test/hyperbolic/linearacoustics.mini

test/navier-stokes/navierstokes_2d_dg_quadrilateral.mini

test/navier-stokes/navierstokes_3d_dg_quadrilateral.mini

test/nonlinear/diffusivewave.mini

...imension-grid-variations/poisson_2d_cg_quadrilateral.mini

...imension-grid-variations/poisson_2d_dg_quadrilateral.mini

...n/dimension-grid-variations/poisson_3d_cg_hexahedron.mini

...n/dimension-grid-variations/poisson_3d_dg_hexahedron.mini

test/poisson/opcount_poisson_dg_symdiff.mini

test/poisson/poisson_dg_quadrilateral.mini

test/poisson/poisson_dg_tensor.mini

test/stokes/stokes_3d_dg_quadrilateral.mini

test/stokes/stokes_3d_quadrilateral.mini

test/stokes/stokes_dg_quadrilateral.mini

test/stokes/stokes_quadrilateral.mini