Update the APIOPS model to reflect the underlying APIM model changes introduced as part of supporting Circuit breaker and load balancers

[waelkdouh]

This is in reference to these two announcements:

https://azure.microsoft.com/en-us/updates/public-preview-load-balancer-in-azure-api-management/ http://azure.microsoft.com/en-us/updates/public-preview-circuit-breaker-in-azure-api-management/