[1.8.x] Fixed #24698, #24712 -- Added ForeignKey.get_db_prep_value()

Fixed crashes with ForeignKey to UUIDField and inheritance with UUIDField
primary keys.

tests/model_fields/models.py

@@ -375,3 +375,11 @@ class PrimaryKeyUUIDModel(models.Model):
 
 class RelatedToUUIDModel(models.Model):
     uuid_fk = models.ForeignKey('PrimaryKeyUUIDModel')
+
+
+class UUIDChild(PrimaryKeyUUIDModel):
+    pass
+
+
+class UUIDGrandchild(UUIDChild):
+    pass