IsAuthorizedForSignerName returns true if 'info' is authorized to perform the given
'verb' on the synthetic 'signers' resource with the given signerName.
If the user does not have permission to perform the 'verb' on the given signerName,
it will also perform an authorization check against {domain portion}/*, for example
`kubernetes.io/*`. This allows an entity to be granted permission to 'verb' on all
signerNames with a given 'domain portion'.