Also, enable HSFC for 2d grids.

We want to sort after correcting the element orientation,
because in the 2-3 grid the convention is, that it is oriented by
the orientation of the first inserted element.

added dimension == 2 to if-clause for recreateboundaryids as it basically reorientates the boundaroies

for some reason you cannot use 999 as bounadryid for hte fake boundaries, because then the linkage breaks

structured the 2d test more like the 3d test with a loadbalance after construction

error in communicator - in this version it always defaulted to the default
non parallel CollectiveCommunicator. CreateBoundaries is also called for
local geometry creation for which the non parallel default is correct. This
should be solved by getting the right type from the GridType.