Modern Label printing (#724)

* Basic widget

* Redirect label printing action

* Refactor label printing code

* Construct form elements

* Refactor to allow re-use of forms

* Basic rendering of label printing form

* Remove dead code

* Pass custom handler through to form context

* Refactoring API forms:

- Allow custom pk field name
- Add callback when values change

* linting

* Dynamically rebuild form

* Handle nested fields

* Handle label printing status

* Run dart format

* Update release notes

* Remove unused var

* Enable close icon

* Handle initial plugin default value

* Store default values:

- Selected template (per label type)
- Selected printing plugin

* Dart format

* Fix dart linting

* use setter

* Just use a public field

lib/widget/part/part_detail.dart

@@ -63,8 +63,6 @@ class _PartDisplayState extends RefreshableState<PartDetailWidget> {
 
   InvenTreePartPricing? partPricing;
 
-  List<Map<String, dynamic>> labels = [];
-
   @override
   String getAppBarTitle() => L10().partDetails;
 
@@ -121,19 +119,13 @@ class _PartDisplayState extends RefreshableState<PartDetailWidget> {
       );
     }
 
-    if (labels.isNotEmpty) {
+    if (allowLabelPrinting && api.supportsModernLabelPrinting) {
       actions.add(
         SpeedDialChild(
           child: Icon(TablerIcons.printer),
           label: L10().printLabel,
           onTap: () async {
-            selectAndPrintLabel(
-              context,
-              labels,
-              widget.part.pk,
-              "part",
-              "part=${widget.part.pk}",
-            );
+            selectAndPrintLabel(context, "part", widget.part.pk);
           },
         ),
       );
@@ -271,26 +263,6 @@ class _PartDisplayState extends RefreshableState<PartDetailWidget> {
         });
       }
     });
-
-    List<Map<String, dynamic>> _labels = [];
-    allowLabelPrinting &= api.supportsMixin("labels");
-
-    if (allowLabelPrinting) {
-      String model_type = api.supportsModernLabelPrinting
-          ? InvenTreePart.MODEL_TYPE
-          : "part";
-      String item_key = api.supportsModernLabelPrinting ? "items" : "part";
-
-      _labels = await getLabelTemplates(model_type, {
-        item_key: widget.part.pk.toString(),
-      });
-    }
-
-    if (mounted) {
-      setState(() {
-        labels = _labels;
-      });
-    }
   }
 
   void _editPartDialog(BuildContext context) {