Migrate "Convert to Variant" form to the API (#3183)

* Adds a Part API filter to limit query to valid conversion options for the specified part

* Refactor 'exclude_tree' filter to use django-filter framework

* Refactor the 'ancestor' filter

* Refactoring more API filtering fields:

- variant_of
- in_bom_for

* Adds API endpoint / view / serializer for converting a StockItem to variant

* stock item conversion now perfomed via the API

* Bump API version

* Add unit tests for new filtering option on the Part list API endpoint

* Adds  unit test for "convert" API endpoint functionality

InvenTree/stock/views.py

@@ -6,10 +6,9 @@ from django.utils.translation import gettext_lazy as _
 from django.views.generic import DetailView, ListView
 
 import common.settings
-from InvenTree.views import AjaxUpdateView, InvenTreeRoleMixin, QRCodeView
+from InvenTree.views import InvenTreeRoleMixin, QRCodeView
 from plugin.views import InvenTreePluginViewMixin
 
-from . import forms as StockForms
 from .models import StockItem, StockLocation
 
 
@@ -133,32 +132,3 @@ class StockItemQRCode(QRCodeView):
             return item.format_barcode()
         except StockItem.DoesNotExist:
             return None
-
-
-class StockItemConvert(AjaxUpdateView):
-    """View for 'converting' a StockItem to a variant of its current part."""
-
-    model = StockItem
-    form_class = StockForms.ConvertStockItemForm
-    ajax_form_title = _('Convert Stock Item')
-    ajax_template_name = 'stock/stockitem_convert.html'
-    context_object_name = 'item'
-
-    def get_form(self):
-        """Filter the available parts."""
-        form = super().get_form()
-        item = self.get_object()
-
-        form.fields['part'].queryset = item.part.get_conversion_options()
-
-        return form
-
-    def save(self, obj, form):
-        """Convert item to variant."""
-        stock_item = self.get_object()
-
-        variant = form.cleaned_data.get('part', None)
-
-        stock_item.convert_to_variant(variant, user=self.request.user)
-
-        return stock_item