Add setting for raft middle layer count

Since the top layer can now have a different extruder, you might want to have a more normal raft layers.

Contributes to issue CURA-8915.

resources/definitions/fdmprinter.def.json

@@ -5642,7 +5642,7 @@
                     "enabled": "resolveOrValue('adhesion_type') == 'raft'",
                     "settable_per_mesh": false,
                     "settable_per_extruder": true,
-                    "limit_to_extruder": "raft_interface_extruder_nr"
+                    "limit_to_extruder": "raft_surface_extruder_nr"
                 },
                 "raft_surface_thickness":
                 {
@@ -5692,6 +5692,19 @@
                     "settable_per_extruder": true,
                     "limit_to_extruder": "raft_surface_extruder_nr"
                 },
+                "raft_interface_layers":
+                {
+                    "label": "Raft Middle Layers",
+                    "description": "The number of layers between the base and the surface of the raft. These comprise the main thickness of the raft. Increasing this creates a thicker, sturdier raft.",
+                    "type": "int",
+                    "default_value": 1,
+                    "minimum_value": "0",
+                    "maximum_value_warning": "10",
+                    "enabled": "resolveOrValue('adhesion_type') == 'raft'",
+                    "settable_per_mesh": false,
+                    "settable_per_extruder": true,
+                    "limit_to_extruder": "raft_interface_extruder_nr"
+                },
                 "raft_interface_thickness":
                 {
                     "label": "Raft Middle Thickness",
@@ -5703,7 +5716,7 @@
                     "minimum_value": "0.001",
                     "minimum_value_warning": "0.04",
                     "maximum_value_warning": "0.75 * machine_nozzle_size",
-                    "enabled": "resolveOrValue('adhesion_type') == 'raft'",
+                    "enabled": "resolveOrValue('adhesion_type') == 'raft' and raft_interface_layers > 0",
                     "settable_per_mesh": false,
                     "settable_per_extruder": true,
                     "limit_to_extruder": "raft_interface_extruder_nr"
@@ -5719,7 +5732,7 @@
                     "minimum_value": "0.001",
                     "minimum_value_warning": "machine_nozzle_size * 0.5",
                     "maximum_value_warning": "machine_nozzle_size * 3",
-                    "enabled": "resolveOrValue('adhesion_type') == 'raft'",
+                    "enabled": "resolveOrValue('adhesion_type') == 'raft' and raft_interface_layers > 0",
                     "settable_per_mesh": false,
                     "settable_per_extruder": true,
                     "limit_to_extruder": "raft_interface_extruder_nr"
@@ -5735,7 +5748,7 @@
                     "minimum_value": "0",
                     "minimum_value_warning": "raft_interface_line_width",
                     "maximum_value_warning": "15.0",
-                    "enabled": "resolveOrValue('adhesion_type') == 'raft'",
+                    "enabled": "resolveOrValue('adhesion_type') == 'raft' and raft_interface_layers > 0",
                     "settable_per_mesh": false,
                     "settable_per_extruder": true,
                     "limit_to_extruder": "raft_interface_extruder_nr"