[MetricsAdvisor] Remove AZC0007 NoWarn option

[kinelski]

Blocked by: Azure/azure-sdk-tools#127

Our guidelines state that:

If the options type can be shared by multiple client types, name it with a plural or more general name. For example, the BlobClientsOptions class can be used by BlobClient, BlobContainerClient, and BlobAccountClient.

We can't create a MetricsAdvisorClientsOptions (pluralized "Clients") because the API analyzer expects a ClientOptions suffix. A NoWarn property was added to avoid the warning for the time being.

[pallavit]

@kinelski is this still valid?

[kinelski]

@kinelski is this still valid?

We don't seem to get the warning anymore. I'll create a PR to update the code and close this issue.