Changes to Retry custom plan billing

added the optional property data/end_date to the response with the 200 status

added the new end_date_must_be_future enum value to the data/problems/items/code response property for the response status 200

added the new end_date_needs_new_subscription enum value to the data/problems/items/code response property for the response status 200

added the new end_date_not_after_renewal_date enum value to the data/problems/items/code response property for the response status 200

added the new optional request property end_date

added the new checkout_superseded enum value to the data/problems/items/code response property for the response status 200

added the optional property data/checkout_id to the response with the 200 status

added the required property data/problems to the response with the 200 status

added the new amendment enum value to the data/plan_billing_source/allOf[#/components/schemas/PlanBillingSource] response property for the response status 200

added the optional property data/migration_id to the response with the 200 status

added the new optional request property billing_start_date

added the optional property data/billing_start_date to the response with the 200 status

added the new optional request property billing_cycle_anchor

added the new optional request property prorate_first_period

added the optional property data/prorate_first_period to the response with the 200 status

added the optional property data/billing_cycle_anchor to the response with the 200 status

added the required property data/plan_billing_source to the response with the 200 status

added the new optional request property send_invoice

added the required property data/send_invoice to the response with the 200 status

removed the request property pay_in_advance

added the optional property data/external_invoice_id to the response with the 200 status