Fix T55470: Add option to not fix polygons' winding to Edit Normals modifier.

this is actually adding option to add buggy behavior, but.. NPR often
expects buggy behaviors, and its one of the main targets for normal editing.
So think it's reasonable to add that option (disabled by default of
course).

Note that am not really happy with UI, but:
* Not sure where to put it, it's kind of own self-contained area option.
* Don't to make it too much visible, using this should be the exception!

release/scripts/startup/bl_ui/properties_data_modifier.py

@@ -1509,6 +1509,7 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
 
     def NORMAL_EDIT(self, layout, ob, md):
         has_vgroup = bool(md.vertex_group)
+        do_polynors_fix = not md.no_polynors_fix
         needs_object_offset = (((md.mode == 'RADIAL') and not md.target) or
                                ((md.mode == 'DIRECTIONAL') and md.use_direction_parallel))
 
@@ -1538,7 +1539,9 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
         sub = row.row(align=True)
         sub.active = has_vgroup
         sub.prop(md, "invert_vertex_group", text="", icon='ARROW_LEFTRIGHT')
-        subcol.prop(md, "mix_limit")
+        row = subcol.row(align=True)
+        row.prop(md, "mix_limit")
+        row.prop(md, "no_polynors_fix", text="", icon='UNLOCKED' if do_polynors_fix else 'LOCKED')
 
     def CORRECTIVE_SMOOTH(self, layout, ob, md):
         is_bind = md.is_bind