Enable more joystick functions

[Achllle]

Problem statement

We currently use teleop_twist_joy to convert joy messages to Twist messages which allows us to maintain less code and rely on tried and true libraries. However it means we're restricted in what we can do:

• no tweaking of mapping function type from joystick movement to twist. Right now that mapping seems linear (need to verify) while it would be good to have some kind of exponential mapping so that steering and acceleration is not as sensitive
• we can't use button switches to perform things like changing drive mode to effort or adjusting PID values out of the box

Potential solutions

• fork the library and modify it to include these functions
• use the library as is but write a separate node that also listens to the /joy topic. This might lead to a bit of hackiness.