Support in-flight checks of shape paremeters

What would you like to be added: When the user chooses a bare metal shape that requires the PV_TRANSIT_ENCRYPTION to be false we should fast-fail before trying to launch a cluster. As a part of this we should look at other checks we should preform.

Why is this needed: The user experience with in-flight encryption is somewhat hostile in that they aren't informed the cluster will fail until the machines fail to start.