Change tests depending on KeyRing change propagation to stop using sleep, and instead use mocks or multi-event barrier

[tegefaulkes]

Specification

When doing a keys renew/reset, the KeyRing dispatches an event with the new information. The PolykeyAgent then handles this event and triggers all the other domains to update in a single handler.

All of this happens in the background, so when a key updates it takes some time for all changes to propagate. This means there are some tests that depend on sleeping for keys to update.

To fix this, the PolykeyAgent needs to dispatch an event to signal that all downstream changes have been done.

Optionally we can a similar event for each domain reacting to the update. Depending on the level of depth we want to do.

After adding the event or events, we need to update all tests that do a key change to use this event instead of using sleep().

The CLI will need it's own tests updated after fixing this.

Additional context

• Related 6th Testnet Deployment #551
• Related 6th Testnet Deployment #551 (comment)

Tasks

1. add an event or events that signify that domains reacting to a keys change have completed it's changes.
2. Client handlers for keys renew and reset need to wait for this event before ending. This will mean that the keys have fully propagated when the CLI command ends.
3. Update tests to not use a sleep() in favour of this event.

[CMCDragonkai]

Related to #386?

[CMCDragonkai]

A couple ways to do this:

1. In terms of fixing this, just mock the handler - wrap the old implementation, and then run an additional function at the end, or something.
2. Your handler should listen on all the state change events like a barrier, and then execute when done.