Label printing fix (#489)

* Add check for modern label printing interface

* Update getLabelTemplates

* Fix typo

* Refactor / simplify

* Revert parameter type

* Update version number and release notes

* Refactor label printing function

- Will require some cleanup in the future
- Still needs testing

* Fix for modern printing

* Typo fix

lib/widget/stock/stock_detail.dart

@@ -138,6 +138,7 @@ class _StockItemDisplayState extends RefreshableState<StockDetailWidget> {
             selectAndPrintLabel(
                 context,
                 labels,
+                widget.item.pk,
                 "stock",
                 "item=${widget.item.pk}"
             );
@@ -264,10 +265,17 @@ class _StockItemDisplayState extends RefreshableState<StockDetailWidget> {
 
     // Request information on labels available for this stock item
     if (allowLabelPrinting) {
+
+      String model_type = api.supportsModenLabelPrinting ? InvenTreeStockLocation().MODEL_TYPE : "stock";
+      String item_key = api.supportsModenLabelPrinting ? "items" : "item";
+
       // Clear the existing labels list
-      _labels = await getLabelTemplates("stock", {
-        "item": widget.item.pk.toString()
-      });
+      _labels = await getLabelTemplates(
+          model_type,
+          {
+              item_key: widget.item.pk.toString()
+          }
+      );
     }
 
     if (mounted) {