Sculpt: Add normal orientation to lasso trim tool

This adds an option to orientate the trimming shape using the surface
normal instead of the view when lasso trim is used.

Reviewed By: dbystedt, sergey

Differential Revision: https://developer.blender.org/D9231

release/scripts/startup/bl_ui/space_toolsystem_toolbar.py

@@ -1320,6 +1320,7 @@ class _defs_sculpt:
         def draw_settings(_context, layout, tool):
             props = tool.operator_properties("sculpt.trim_lasso_gesture")
             layout.prop(props, "trim_mode", expand=False)
+            layout.prop(props, "trim_orientation", expand=False)
             layout.prop(props, "use_cursor_depth", expand=False)
         return dict(
             idname="builtin.lasso_trim",