python interface: extract out print_method_header
python interface: extract out print_method_header

This makes it easier to modify the way the header is printed and
allows the header printing to be reused in a subsequent commit.

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

tobig/isl,inducer/isl-mirror,BenzoSM/isl,BenzoSM/isl,PollyLabs/isl,UBERTC/isl,Distrotech/isl,tobig/isl,Meinersbur/isl,Meinersbur/isl,nicolasvasilache/isl,tobig/isl,UBERTC/isl,inducer/isl-mirror,inducer/isl-mirror,Meinersbur/isl,Distrotech/isl,tobig/isl,Distrotech/isl,Meinersbur/isl,Distrotech/isl,BenzoSM/isl,nicolasvasilache/isl,inducer/isl-mirror,Distrotech/isl,PollyLabs/isl,nicolasvasilache/isl,nicolasvasilache/isl,inducer/isl-mirror,BenzoSM/isl,BenzoSM/isl,PollyLabs/isl,UBERTC/isl,PollyLabs/isl,PollyLabs/isl,UBERTC/isl,nicolasvasilache/isl