[WIP] Cancellation test

[Menduist]

Start of the cancellation test:

• Adding awaitrc on cleanup to avoid cleanup being cancelled (and thus, leaks)
• Adding a cancelTest which is cancelling every step of the way
• Adding a simple connect test for now

Few notes:
The cancel test works like that:

    for i in 0..1000:
      echo "polling ", i ," times"
      let testFuture = cancelledTest()
      for _ in 0..<i:
        if testFuture.finished: break
        poll()
      if testFuture.finished: break

Poll is emptying the callback list, so a "computation only" future will only poll once.
For poll to return, there needs to be a IO wait or something like that.

So this is only testing cancellation a "IO operations"!

This is already good enough to leak on a simple connect, but not perfect yet.
(The simple connect test has 143 poll, but a simple switch start/stop has 1 poll)

awaitrc or equivalent should move to chronos