speed up barkd tests

My goal was to speed up the barkd test-suite. It seems some of the benefits are extended further to other tests. I see that this usually ends up with a CI-time between 15 and 17 minutes. Master usually runs between 17 and 19 minutes so I believe this is significantly faster.

The key change is that I added zmq. This ensures all cases where we wait on blocks (we do this a lot) get processed immediately instead of waiting for a poll-rate.

I also removed some waits.