ManagementLocks_Get in resource/locks incorrect + missing operations

[lmazuel]

The way the "scope" is made in the "lock" RestApi implies that each call to the RestApi must be translated in three operations in the Swagger file:

• At Subscription Level
• At Resource Group Level
• At Resource Level

For instance, we have for "create_or_update":

• ManagementLocks_CreateOrUpdateAtSubscriptionLevel
• ManagementLocks_CreateOrUpdateAtResourceGroupLevel
• ManagementLocks_CreateOrUpdateAtResourceLevel

However the "get" operation is currently defined as:

        "operationId": "ManagementLocks_Get",
        "description": "Gets the management lock of a scope.",

which let us suppose that it's a generic operation able to get the three scopes. Unfortunately, this get is the "subscription_level" get.

We need to:

• Rename ManagementLocks_Get to ManagementLocks_GetAtSubscriptionLevel
• Add ManagementLocks_GetAtResourceGroupLevel
• Add ManagementLocks_GetAtResourceLevel