Cert: add common helper for event stream on the py side

* add common helper for event stream on the py side, implement
  assert_event_occurs in the helper
* add event stream helpers for hci event, sco and acl in GdDevice
* add take_for() function in BlockingQueue for take data with timeout

Test: run gd/cert/run_cert.sh
Change-Id: Ia8168159ee47441ec332046627124e0ed3811d6b