[!135] removed unused macro DIM_MAX that conflects with an Alberta macro

Merge branch 'issue/unused_macros_dim_max' into 'master'

ref:staging/dune-uggrid The macros DIM_MAX and DIM_OF_BND_MAX are not used
anywhere and the DIM_MAX macro conflicts with macros from other libraries. So
they are simply removed. The corresponding `#undef DIM_MAX` should be removed
from dune-grid.

See merge request [!135]

  [!135]: gitlab.dune-project.org/staging/dune-uggrid/merge_requests/135