Add explicit Scene serialization to binary format

[dokempf]

So far, the parameters rebuildSceneand noSceneWritingimplicitly controlled, when a Sceneobject was (de)serialized to binary format. In the Python API, this could become a much more explicit operation like this:

class Scene:
	def to_binary(self, path: Path):
		# Write to a binary file

	@classmethod
	def from_binary(self, path: Path):
		return Scene...

Implementation would most likely be realized via dedicated C++ functions with respective bindings, like we did for the XML parsing.