There are some important variables in the SSL/TLS cert storage backends

that are currently locked into the file storage backend. This promotes

the following from that backend into the base classes and adds

validation during construction:

BaseStoredCertificate.hostname
BaseStoredCertificate.port
BaseStoredCertificateBundle.name
BaseStoredCertificateFingerprints.hostname
BaseStoredCertificateFingerprints.port

Unit tests pass.