Add Object Tool: make automatic axis selection an option

While useful in some cases, this meant it wasn't possible to use the
"Floor" for object placement without looking top-down or bottom up.

release/scripts/startup/bl_ui/space_toolsystem_toolbar.py

@@ -503,6 +503,7 @@ class _defs_view3d_add:
         if extra:
             layout.use_property_split = True
             layout.row().prop(props, "plane_axis", expand=True)
+            layout.row().prop(props, "plane_axis_auto")
 
             layout.label(text="Base")
             layout.row().prop(props, "plane_origin_base", expand=True)