Control head LEDs via topics/services

[PedroS235]

Describe the solution you'd like Currently, only the driver can change the LEDs color based on the robot status, which is not really giving much information except of warning low battery.

A topic could be created where the user can control the LEDs, where it can be used for custom alerts. In addition, the creating of a custom LED server node could also be created, which would be responsible for taking an action such as blink for x sec with y color, or for instance control the LEDs so that we have a rainbow.