This commit moves the property layout callbacks for node types to their
implementation files from `drawnode.c`. This was proposed a while ago in
T75724.
**Benefits**
- Fewer files need to be changed when adding a new node.
- Makes it possible to reuse functions from the node's implementation
in the layout code.
- Except for RNA, all of the node "inputs" are in the same place.
- Code gets shorter overall, avoids the large switch statements.
**Downsides**
- Requires including two UI headers.
- Requires adding an editors dependency to the nodes folder.
This commit only changes function nodes and geometry nodes, more can be
moved later.
Differential Revision: https://developer.blender.org/D10352
cfa48c84d0