cflib - Crazyflie_example launch with scripts doesn't work for cflib backend

[knmcguire]

The cflib backend takes time to connect the crazyflie due to the slow python threads. However, if the cflib backend is chosen, those examples don't work as the crazyflies aren't initialized in time.

to recreate:

ros2 launch crazyflie_examples launch.py backend:=cflib script:=set_param

Expect to see the crazyflies connect, and then the lights turn off. Unfortunately the crazyflie_py gets an error because the instance was initialized without the parameters being known from the crazyflies. I would guess that the same would hold for all the services since those are not initialized if the crazyflies aren't fully connected (which means that all the paramters and it's values have been downloaded).