Replace support_tree_enable by a support_structure enum

CURA-6711

cura/Settings/ExtruderManager.py

@@ -289,7 +289,7 @@ class ExtruderManager(QObject):
             return global_stack.getProperty("adhesion_extruder_nr", "value")
 
         # No adhesion? Well maybe there is still support brim.
-        if (global_stack.getProperty("support_enable", "value") or global_stack.getProperty("support_tree_enable", "value")) and global_stack.getProperty("support_brim_enable", "value"):
+        if (global_stack.getProperty("support_enable", "value") or global_stack.getProperty("support_structure", "value") == "tree") and global_stack.getProperty("support_brim_enable", "value"):
             return global_stack.getProperty("support_infill_extruder_nr", "value")
 
         # REALLY no adhesion? Use the first used extruder.

resources/definitions/fdmprinter.def.json

@@ -6207,13 +6207,18 @@
             "description": "Features that haven't completely been fleshed out yet.",
             "children":
             {
-                "support_tree_enable":
+                "support_structure":
                 {
-                    "label": "Tree Support",
-                    "description": "Generate a tree-like support with branches that support your print. This may reduce material usage and print time, but greatly increases slicing time.",
-                    "type": "bool",
-                    "default_value": false,
-                    "settable_per_mesh": true,
+                    "label": "Support Structure",
+                    "description": "Generate a tree-like support ",
+                    "type": "enum",
+                    "options":
+                    {
+                        "normal": "Normal",
+                        "tree": "Tree"
+                    },
+                    "default_value": "normal",
+                    "settable_per_mesh": false,
                     "settable_per_extruder": false
                 },
                 "support_tree_angle":

resources/setting_visibility/expert.cfg

@@ -349,7 +349,7 @@ smooth_spiralized_contours
 relative_extrusion
 
 [experimental]
-support_tree_enable
+support_structure
 support_tree_angle
 support_tree_branch_distance
 support_tree_branch_diameter