This PR adds a peer login expiration logic that requires
peers created by a user to re-authenticate (re-login) after
a certain threshold of time (24h by default).
The Account object now has a PeerLoginExpiration
property that indicates the duration after which a peer's
login will expire and a login will be required. Defaults to 24h.
There are two new properties added to the Peer object:
LastLogin that indicates the last time peer successfully used
the Login gRPC endpoint and LoginExpirationEnabled that
enables/disables peer login expiration.
The login expiration logic applies only to peers that were created
by a user and not those that were added with a setup key.