Geometry Nodes: Bounding Box Node

This commit adds a simple node to output the min and max of an
axis-aligned bounding box for the input geometry, as well a rectangular
prism mesh created from these values for convenience.

The initial use case for this node is a "bounding box boolean", where
doing the boolean with just a bounding box could be signigicantly
faster, for cases like cutting a hole in a wall for a window. But it's
easy to imagine other cases where it could be useful.

This node supports mesh and point cloud data right now, volume support
will come as a separate patch. Also note that there is plenty of room
to improve the performance of this node through parallelization.

Differential Revision: https://developer.blender.org/D10420

release/scripts/startup/nodeitems_builtins.py

@@ -505,6 +505,7 @@ geometry_node_categories = [
         NodeItem("ShaderNodeCombineRGB"),
     ]),
     GeometryNodeCategory("GEO_GEOMETRY", "Geometry", items=[
+        NodeItem("GeometryNodeBoundBox"),
         NodeItem("GeometryNodeTransform"),
         NodeItem("GeometryNodeJoinGeometry"),
     ]),