Fix minor issues and remove depricated usage of cumulant LB method

doc/notebooks/03_tutorial_lbm_formulation.ipynb

doc/notebooks/04_tutorial_cumulant_LBM.ipynb

doc/notebooks/demo_create_method_from_scratch.ipynb

lbmpy/creationfunctions.py

lbmpy/methods/centeredcumulant/centeredcumulantmethod.py

lbmpy/methods/creationfunctions.py

lbmpy/methods/momentbased/moment_transforms.py

lbmpy/phasefield_allen_cahn/kernel_equations.py

lbmpy/simplificationfactory.py

...s/phasefield/test_neumann_evaluation_circle_fitting.ipynb

lbmpy_tests/phasefield/test_phasefield.py

lbmpy_tests/test_cumulant_methods.py

lbmpy_tests/test_gpu_block_size_limiting.py

lbmpy_tests/test_momentbased_methods_equilibrium.py

lbmpy_tests/test_serial_scenarios.py