Changes to List user subscriptions

added the optional property data/items/allotment/generations_left to the response with the 200 status

added the optional property data/items/allotment/generations_limit to the response with the 200 status

added the optional property data/items/features to the response with the 200 status

added the optional property data/items/portfolio to the response with the 200 status

added the optional property data/items/price_per_download/content_tiers to the response with the 200 status

added the optional property data/items/product_description to the response with the 200 status

added the optional property errors/items/statusCode to the response with the 200 status

api operation id getUserSubsciptionList removed and replaced with getUserSubscriptionList

added the optional property data/items/allotment/content_tiers to the response with the 200 status