Geometry Nodes: new Switch node

This is a first iteration of a switch node. It can only switch between
two inputs values based on a boolean. A more sophisticated switch
node that has an integer selector will probably come later.

Currently, the geometry nodes evaluator does not support lazy evaluation
of individual inputs. Therefore, all inputs will be computed currently.
An improvement to the evaluator will be worked on separately.

Ref: T85374

Differential Revision: https://developer.blender.org/D10460

release/scripts/startup/nodeitems_builtins.py

@@ -550,6 +550,7 @@ geometry_node_categories = [
         NodeItem("ShaderNodeMath"),
         NodeItem("FunctionNodeBooleanMath"),
         NodeItem("FunctionNodeFloatCompare"),
+        NodeItem("GeometryNodeSwitch"),
     ]),
     GeometryNodeCategory("GEO_VECTOR", "Vector", items=[
         NodeItem("ShaderNodeSeparateXYZ"),