Given an existing contract with a subscription
When we send an update for the contract, internally we're ending the existing subscription and creating a new one
Then if we call the "/subscriptions/products/

" resource, we'll get only one result as expected because we're merging the ended subscription and the new subscription in the following logic: https://github.com/RedHatInsights/rhsm-subscriptions/blob/main/src/main/java/org/candlepin/subscriptions/resource/SubscriptionTableController.java#L148-L180

However, if we export the same data via the export service, we'll get an duplicated record:

[{'sku': 'MW02393',
  'product_name': 'OpenShift Online',
  'service_level': 'Premium',
  'usage': '',
  'org_id': '3340851',
  'subscription_number': '1195000',
  'quantity': 1.0,
  'measurements': []}, <-- this is from the ended subscription
 {'sku': 'MW02393',
  'product_name': 'OpenShift Online',
  'service_level': 'Premium',
  'usage': '',
  'org_id': '3340851',
  'subscription_number': '1195000',
  'quantity': 1.0,
  'measurements': [{'metric_id': 'Cores',
    'capacity': 40.0,
    'measurement_type': 'PHYSICAL'},
   {'metric_id': 'Instance-hours',
    'capacity': 12.0,
    'measurement_type': 'PHYSICAL'}]}] <-- this is from the new subscription

Note that we can't do the same logic of https://github.com/RedHatInsights/rhsm-subscriptions/blob/main/src/main/java/org/candlepin/subscriptions/resource/SubscriptionTableController.java#L148-L180 in the export service because we need to deal with large data here.

Therefore, as a possible solution to be refined, we should refactor the API to do the same but using a view (similar solution as done for the Instances API).

Acceptance Criteria

• Write IQE test to reproduce/verify the issue
• Both "/subscriptions/products/<product_id>" resource and the export service should return exactly the same data and records.