Delegates authentication decisions, and optionally determination of user
roles and schema, to a different HyperSQL catalog, which may be in the same
JVM or remote.
For now, at least, this class uses DriverManager to make the ephemeral
Blaine Simpson (blaine dot simpson at admc dot com)
Return a list of authorized roles or null to indicate that the
implementation does not intend to produce a specific role list but only
to indicate whether to allow access or not.
A return value of String is different from returning null, and means
that the user should not be granted any roles.