Archive related Product when PriceList is deleted

Products and PricedProducts are created when a PriceList is created
or edited. When a PriceList is deleted, the related PricedProduct is
deleted. However, the Product was not deleted/archived. This caused
issues with there being multiple Products for the same resource. Fix
this by archiving the existing Product when a PriceList is deleted.

Refs STAM-24

respa_pricing/models/price.py

@@ -6,6 +6,7 @@
 from django.utils.duration import duration_string
 from django.utils.functional import cached_property
 from django.utils.translation import ugettext_lazy as _
+from django.utils.timezone import now
 
 from payments.utils import (
     convert_aftertax_to_pretax,
@@ -202,6 +203,13 @@ class Meta:
     def __str__(self):
         return self.name
 
+    def delete(self, *args, **kwargs):
+        priced_product = getattr(self, "priced_product", None)
+        if priced_product:
+            priced_product.product.archived_at = now()
+            priced_product.product.save()
+        super().delete(*args, **kwargs)
+
     @cached_property
     def price_type(self):
         price_types = (