[wip/py-prf-ros-control] add a PREFER.pal helper for erbium

Affected packages:
- wip/pal-gazebo-plugins
- wip/pal-gazebo-worlds
- wip/pal-gripper
- wip/pal-hardware-gazebo
- wip/pal-hardware-interfaces
- wip/pal-msgs
- wip/pal-navigation-sm
- wip/pal-transmissions
- wip/pal-wsg-gripper
- wip/prf-roboticsgroup-gazebo-plugins
- wip/prf-teleop-tools
- wip/py-prf-gazebo-ros-pkgs
- wip/py-prf-ros-control
- wip/py-prf-ros-controllers