We want to send email verification reminders to users from the satellite
core, but some of the functionality required to do so exists in the
satellite console service. We could simply import the console service
into the core to achieve this, but the service requires a lot of
dependencies that would go unused just to be able to send these emails.
Instead, we break out the needed functionality into a new service which
can be imported separately by the console service and the future email
chore.
The consoleauth service creates, signs, and checks the expiration of auth
tokens.
Change-Id: I2ad794b7fd256f8af24c1a8d73a203d508069078