split pythonBCs in init and glacialcycle
split the template file for pythonBCs in init and glacialcycle, which reduces unnecessary object creation. We further use the path to only create the necessary BC objects for T / TH / THM. This split helps to prevent issues regarding the upcoming changes for the real geometries. In the init_template.py I removed all unused lines. In the glacicalcycle_template.py I commented them out.
Testet succesfully with Salz-flach 2D/3D xres 500/800 T/TH/THM