Add setting to prevent the top layer from doing small-skin behaviour.

Actually the other way around, so we don't have another negation you have to turn on to turn off (and so the default can be false I suppose). The idea is that recently, a feature was introduced where there should be walls instead of normal skin in small hard to reach places of the model. However, this is to be excluded in most cases for all the top-layer parts exposed to air on the buildplate.

implements CURA-10829

resources/setting_visibility/advanced.cfg

@@ -34,6 +34,8 @@ bottom_thickness
 bottom_layers
 ironing_enabled
 skin_monotonic
+small_skin_width
+small_skin_on_surface
 
 [infill]
 infill_extruder_nr