Point Cloud: Add initial edit mode support

Similar to 5f16e24cc9, this adds support for edit mode
to the point cloud object type, which is currently hidden behind an
experimental option. No interaction is possible yet, for now this
can be used as a testing for a node-group-operator-only mode.

scripts/startup/bl_ui/space_view3d.py

@@ -2102,6 +2102,13 @@ class VIEW3D_MT_select_paint_mask_vertex(Menu):
         layout.operator("paint.vert_select_linked", text="Select Linked")
 
 
+class VIEW3D_MT_select_edit_point_cloud(Menu):
+    bl_label = "Select"
+
+    def draw(_self, _context):
+        pass
+
+
 class VIEW3D_MT_edit_curves_select_more_less(Menu):
     bl_label = "Select More/Less"
 
@@ -5478,6 +5485,13 @@ class VIEW3D_MT_edit_curves(Menu):
         layout.operator("curves.delete")
 
 
+class VIEW3D_MT_edit_pointcloud(Menu):
+    bl_label = "Point Cloud"
+
+    def draw(_self, _context):
+        pass
+
+
 class VIEW3D_MT_object_mode_pie(Menu):
     bl_label = "Mode"
 
@@ -8220,6 +8234,7 @@ classes = (
     VIEW3D_MT_select_edit_gpencil,
     VIEW3D_MT_select_paint_mask,
     VIEW3D_MT_select_paint_mask_vertex,
+    VIEW3D_MT_select_edit_point_cloud,
     VIEW3D_MT_edit_curves_select_more_less,
     VIEW3D_MT_select_edit_curves,
     VIEW3D_MT_select_sculpt_curves,
@@ -8347,6 +8362,7 @@ classes = (
     VIEW3D_MT_edit_armature_delete,
     VIEW3D_MT_edit_gpencil_transform,
     VIEW3D_MT_edit_curves,
+    VIEW3D_MT_edit_pointcloud,
     VIEW3D_MT_object_mode_pie,
     VIEW3D_MT_view_pie,
     VIEW3D_MT_transform_gizmo_pie,