Use value to override settings that were a value in the parent def

Contributes to issue CURA-8782.

resources/definitions/mixware_hyper_s.def.json

@@ -80,10 +80,10 @@
             "default_value": "zigzag"
         },
         "support_infill_rate": {
-            "default_value": "15"
+            "value": 15
         },
         "gantry_height": {
-            "default_value": 25
+            "value": 25
         },
         "machine_max_feedrate_x": {
             "default_value": 500
@@ -148,9 +148,6 @@
         "infill_sparse_density": {
             "default_value": 15
         },
-        "infill_before_walls": {
-            "default_value": false
-        },
         "fill_perimeter_gaps": {
             "default_value": "everywhere"
         },
@@ -321,10 +318,10 @@
             "value": "line_width * 2"
         },
         "acceleration_travel": {
-            "default_value": 1000
+            "value": 1000
         },
         "line_width": { 
-            "default_value": "0.4" 
+            "value": 0.4
         },
         "speed_z_hop": { 
             "default_value": 5