Monitor or extend session key expiration

[BigLep]

With #416 we added session keys. The expiration was set to 90 days. We either should have monitoring on the expiration so we get notified to extend or we just extend this to be the distant future (e.g., 5 years) and we don't worry about it.

[BigLep]

This will get handled implicitly when we generate a new session key as a result of updating to a new Synapse version that encompases FilOzone/synapse-sdk#726 . Lets make the session key live longer (infinite) so we don't have to monitor. For safety, we always have the option to revoke the session key.