Eliminate requirement for permission to “Manage Secure Execution Keys” task

[andy-maier]

On z16, the exporter currently requires permission for the “Manage Secure Execution Keys” task for the HMC userid that is used.

This is a new task on z16 and is required to perform the ‘Get CPC Properties’ operation, where some of the returned properties require that permission.

Since these properties are not used by the exporter, it would be good if the requirement for the permission could be dropped by performing the ‘Get CPC Properties’ operation with specific properties that are needed, instead of pulling all of them. This requires some care, because the default behavior of the zhmcclient library when a property is accessed that is not locally present, is to pull all properties.