Subscriptions test definitions: wrong property paths and remaining findings (follow-up to #120, #121) #136

Problem description
Findings in the subscriptions test definitions of the r2.2 snapshot:

• device-data-volume-subscriptions-createDeviceDataVolumeSubscription.feature:
  • L147 uses $.subscriptionExpireTime and L159 $.subscriptionMaxEvents; both are properties of config ($.config.subscriptionExpireTime, $.config.subscriptionMaxEvents).
  • L161 refers to subscription property $.type; the property is $.types.
  • Scenario titles still name consumed instead of remaining percentages (Subscriptions API: info.description doesn't match the actual event/threshold model #121): "data-75-percent event" (L109) for data-25-percent-remaining, "data-90-percent event" (L121) for data-10-percent-remaining, and "data-exceeded event" (L133) for data-00-percent-remaining.
  • L207: "Create roaming status subscription" is left over from another API.
• The 401 scenarios of retrieveDeviceDataVolumeSubscription (L91, L102, L113) and deleteDeviceDataVolumeSubscription (L63, L74, L85) require a request body compliant with SubscriptionRequest; these operations have no request body.
• Scenarios requested in Subscriptions API: test definitions reference nonexistent schemas/properties and use inconsistent status wording #120 are neither added nor marked as deferred:
  • 409 on create (create feature L449: "No tests cases yet defined")
  • 403 on list (list feature L197: "No test cases yet defined"); the same applies to retrieve and delete by id
  • subscription-started and subscription-updated notifications

Expected action

• Correct the property paths, the scenario titles and the leftover wording.
• Remove the SubscriptionRequest body condition from the retrieve and delete 401 scenarios.
• Add the missing scenarios, or record in an issue that they are deferred.

Additional context
Found during release review of #133. Follow-up to #120 and #121.