Add support for "Forever" SLA in objectID

[drew-russell]

What would you like to be added:

When the objectID object_type is sla we should add a check for forever or unprotected as the objectName. If detected, we should then return "UNPROTECTED" as the SLA ID

Code logic from Python SDK

if object_name.upper() == "FOREVER" or object_name.upper() == "UNPROTECTED":
                return "UNPROTECTED"

https://github.com/rubrikinc/rubrik-sdk-for-go/blob/devel/rubrikcdm/data_management.go#L70

Why is this needed:

Match full functionality of the GUI and allow support for unmanaged snapshots