Arm / Create display-only (rviz only) launch file.

Launch file should launch:
TF2 static transform (see what's under the "composite"
RViz2 - with the same config as the bringup launch file (or another custom config file, but it needs to load in the robot model and stuff)
robot state publisher


Basically everything except for joy and the custom servo node. I'd start by duplicating the dev_arm_bringup.launch.py file 
