feat: print thin walls setting (CURA-4023)

resources/definitions/fdmprinter.def.json

@@ -1125,6 +1125,14 @@
                     "limit_to_extruder": "wall_0_extruder_nr",
                     "settable_per_mesh": true
                 },
+                "fill_outline_gaps": {
+                    "label": "Print Thin Walls",
+                    "description": "Print pieces of the model which are horizontally thinner than the nozzle size.",
+                    "type": "bool",
+                    "default_value": "false",
+                    "limit_to_extruder": "wall_0_extruder_nr",
+                    "settable_per_mesh": true
+                },
                 "xy_offset":
                 {
                     "label": "Horizontal Expansion",