Add option to show part quantity in various forms

Enabling this option can make BOM item forms *very* slow!

InvenTree/common/models.py

@@ -160,6 +160,13 @@ class InvenTreeSetting(models.Model):
             'validator': bool,
         },
 
+        'PART_SHOW_QUANTITY_IN_FORMS': {
+            'name': _('Show Quantity in Forms'),
+            'description': _('Display available part quantity in some forms'),
+            'default': True,
+            'validator': bool,
+        },
+
         'STOCK_ENABLE_EXPIRY': {
             'name': _('Stock Expiry'),
             'description': _('Enable stock expiry functionality'),