Minor Fixes + 1 New test case

1. [add] New Test case - Deploy and Check all VM sizes and rerun the test in Loop. [Helpful in finding deployment related issues.]
2. [fix] CheckVMsInService() : Better exception handling.
3. [fix] Removed "-ErrorAction SilentlyContinue" from Azure commands so that azure error logs will be visible on screen. [Helpful in command execution fail scenarios.]