added patch for ros-noetic-joy that falls back to sdl2

[TedVanderfeen]

See https://github.com/RoboStack/ros-noetic/issues/548

Creating as draft for now until I've had a chance to test it.

The code for the joy_node_sdl is from here with some edits by me so that it loads the default mappings into params if none are provided. This gets around needing to use the launch file that the devs above implemented if you just want "normal" behaviour when launching the node. I also fixed up some of the logic they had in the cmakelist for joy as it was a little confusing.

See https://github.com/TedVanderfeen/joystick_drivers for the changes that went into generating the .patch file.