Structural categories (#220)

* Add support for editing "structural" tree field

- Requires API v83 or newer

* Update release notes

assets/release_notes.md

@@ -1,6 +1,14 @@
 ## InvenTree App Release Notes
 ---
 
+### - December 2022
+---
+
+- Add support for structural part categories
+- Add support for structural stock locations
+- Updated translations
+
+
 ### 0.8.3 - September 2022
 ---
 

lib/api.dart

@@ -259,6 +259,9 @@ class InvenTreeAPI {
   // Notification support requires API v25 or newer
   bool get supportsNotifications => isConnected() && apiVersion >= 25;
 
+  // Structural categories requires API v83 or newer
+  bool get supportsStructuralCategories => isConnected() && apiVersion >= 83;
+
   // Are plugins enabled on the server?
   bool _pluginsEnabled = false;
 

lib/inventree/part.dart

@@ -25,11 +25,18 @@ class InvenTreePartCategory extends InvenTreeModel {
   @override
   Map<String, dynamic> formFields() {
 
-    return {
+    Map<String, dynamic> fields = {
       "name": {},
       "description": {},
-      "parent": {}
+      "parent": {},
+      "structural": {},
     };
+
+    if (!api.supportsStructuralCategories) {
+      fields.remove("structural");
+    }
+
+    return fields;
   }
 
   String get pathstring => (jsondata["pathstring"] ?? "") as String;

lib/inventree/stock.dart

@@ -652,13 +652,18 @@ class InvenTreeStockLocation extends InvenTreeModel {
 
   @override
   Map<String, dynamic> formFields() {
-    return {
+    Map<String, dynamic> fields = {
       "name": {},
       "description": {},
-      "parent": {
+      "parent": {},
-
+      "structural": {},
-      },
     };
+
+    if (!api.supportsStructuralCategories) {
+      fields.remove("structural");
+    }
+
+    return fields;
   }
 
   String get parentPathString {