add open merge requests from pystencils_walberla
pystencils_walberla was moved into the main walberla repo but pycodegen/pystencils_walberla!5 (closed) was still open this merges the missing merge requests
Edited by Michael Kuron
pystencils_walberla was moved into the main walberla repo but pycodegen/pystencils_walberla!5 (closed) was still open this merges the missing merge requests