Joystick pair only one controller at once

[Benvii]

As a animator I want to be able to use all controllers with all cars, as it's going to be too complexe to know which controller goes with which car, but I only want one controller at a time by cars.

Keep in mind that we might have 2-3 cars at the same time on the circuit.

For it we need to modify ds4drv, maybe add a number of controllers in it. We also need to handle edge case (controlleur is disconnected pairing an other one..).

[Benvii]

Issue created here : chrippa/ds4drv#193

PR here : chrippa/ds4drv#194