Managed cache scenario test (can run under mock)

Notes (please read)

To get the test run mocked, I will have to fix up the service name and region for 2 reasons so that the HTTP mock will be able to find match:
     a. The cache service needs parent cloud service to create first and its name will need to be calculated based on region and subscription name. If i change region name in test, then mock can't match during playback.
     b. The PS doesn't have smart matching with random name, though hydra-spec has, and we can improve. 

I create a static field inside TestMockSupport to mark the test is undr mock or not for 2 reasons:
     a. The PS has a step of 'resource provider registration' which doesn't go through HTTP mock server, and we need a way to bypass it.
     b. The poll delay in the command is too significant that slow down the test badly, and we need a way to bypass it.