message: [test] Add functionality to AddrReceiver
  Add two simple helper functions to `AddrReceiver` to support callers currently
  using `GetAddrStore` [used in next commit].
diff: @@ -40,6 +40,12 @@ class AddrReceiver(P2PInterface):
  raise AssertionError("Invalid addr.port of {} (8333-8342 expected)".format(addr.port))
  assert addr.ip.startswith('123.123.123.')
  + def addr_received(self):
  + return self.num_ipv4_received != 0
  +
  + def getaddr_received(self):
  + return self.message_count['getaddr'] > 0
  +
  class GetAddrStore(P2PInterface):
  getaddr_received = False
  