Better node settings replication functions

[BrendanParmer]

There is a lot of duplicated code for handling different node setting types. It'd be nice to define an interface that can automatically replicate settings, cleaning up the current code and making future Blender changes easier to maintain. Ideally we could extend the node settings generation script to handle this task, as well.

[BrendanParmer]

This could probably be extended to all sorts of types to be replicated (e.g. scenes, worlds, modifiers, etc). Maintenance would surely get a lot easier if all that needs done is just to define a (bpy.types._) -> py_str function for new types.