Geometry Nodes: Expose sharp edge status with builtin nodes

Change the existing "Is Shade Smooth" node to be named "Is Face Smooth"
and add a new "Is Edge Smooth" node. Also give the "Set Shade Smooth"
node the ability to set face smoothness, edge smoothness, or both.

The face that sharpness is stored separately on two domains makes the
best design for simple operations non-obvious. Fr example, you should be
able to remove all sharpness or make everything flat with a single node.
The behavior depends on whether the two attributes exist and the
combination of values between the domains. That leads to the mode
toggle on the "Set Shade Smooth" node, which gives complete control
but helps to keep things simple as well.

The fact that the nodes process "smooth" data reversed from the builtin
"sharp" attributes can be reversed with versioning in a separate commit.

While it's tempting to abstract the sharpness status into a single node,
face and edge smoothness are accessed separately in edit mode, and the
sublety of interacting with data on different domains would make that
confusing. Instead, a separate "Is Shade Smooth" node group asset will
give all the sharp elements taking into account both builtin attributes.

@@ -1034,0 +1036,4 @@
+    LISTBASE_FOREACH (bNodeTree *, ntree, &bmain->nodetrees) {
+      if (ntree->type == NTREE_GEOMETRY) {
+        LISTBASE_FOREACH (bNode *, node, &ntree->nodes) {
+          if (STREQ(node->idname, "GeometryNodeSetShadeSmooth")) {