change serializer

[PythonFZ]

• check backwards compatibility
• fix Order in zn.Method() #225

This PR is best described by the new params.yaml / znrack.json split, now including the _cls as a parameter.

ZnTrack/tests/integration_tests/test_zn_methods.py

Lines 169 to 179 in 0a91c7a

	def zntrack_params_dict() -> (dict, dict):
	zntrack_dict = {
	"SingleNodeNoParams": {
	"data_class": {"_type": "zn.method", "value": {"module": "test_zn_methods"}}
	}
	}
	params_dict = {
	"SingleNodeNoParams": {
	"data_class": {"_cls": "ExampleMethod", "param1": 1, "param2": 2}
	}
	}

vs. the old one

ZnTrack/tests/integration_tests/test_zn_methods.py

Lines 211 to 219 in 0a91c7a

	zntrack_dict = {
	"SingleNodeNoParams": {
	"data_class": {
	"_type": "zn.method",
	"value": {"cls": "ExampleMethod", "module": "test_zn_methods"},
	}
	}
	}
	params_dict = {"SingleNodeNoParams": {"data_class": {"param1": 1, "param2": 2}}}