Revert "[assembler.system] don't hardcode local codim0 matrix assembler type"
Revert "[assembler.system] don't hardcode local codim0 matrix assembler type"

This reverts commit b66046d56855b3dad5ff34e3edce9a4baa0e9789.

ftalbrecht/dune-gdt,BarbaraV/dune-gdt