More fixes

- Allow stock item creation for inactive parts
- Better handling of successful stock item creation
- Disable fields rather than hiding them

InvenTree/stock/models.py

@@ -456,7 +456,6 @@ class StockItem(MPTTModel):
         verbose_name=_('Base Part'),
         related_name='stock_items', help_text=_('Base part'),
         limit_choices_to={
-            'active': True,
             'virtual': False
         })