Improve and fix update process

[lsd-cat]

Currently the update function always tries to update if there's a new block. However, there could be a new block but not a new list state and as such the canonical rot hash might be the same. Currently, this is hidden in https://github.com/freedomofpress/ics23-ts but the info should be made available and verified to the caller.

[lsd-cat]

Update on this: while it is better, the setTimeout based approach seems to fail when there's sleep or suspensions in between. As a note, we should probably also do time-based checks.