This has some benefits:
* Nodes with dynamic socket amounts can remain more self-contained
(2 fewer files to edit with this patch).
* It's easier to reuse existing C++ code, reducing redundancy.
One new thing I'm doing here is to define operators in node files. It seems
reasonable to register operators that belong to a node together with that
node. Without this, code spreads out further than necessary without any real benefit.
This patch affects the simulation zone, repeat zone, bake node and index switch node.
The UI is slightly affected too. Since we had the UI defined in Python before,
it wasn't possible to integrate it into the node properties panel. That is possible
now and looks better anyway. The previous UI was an artifact of technical limitations.
Pull Request: https://projects.blender.org/blender/blender/pulls/121178
0c585a1b8a