add bindings for kernel

pythonbindings/pyfluids-stubs/gpu/__init__.pyi

pythonbindings/pyfluids-stubs/gpu/kernel/__init__.pyi

pythonbindings/pyfluids-stubs/gpu/kernel/compressible.pyi

pythonbindings/pyfluids-stubs/gpu/kernel/incompressible.pyi

pythonbindings/pyfluids-stubs/gpu/kernel/porous_media.pyi

pythonbindings/pyfluids-stubs/gpu/kernel/wale.pyi

pythonbindings/src/gpu/gpu.cpp

pythonbindings/src/gpu/submodules/kernel.cpp

pythonbindings/src/gpu/submodules/parameter.cpp