RobotPower With Time Delay Needed

[shamlian]

Discussed in #254

^{Originally posted by slowrunner November 25, 2022}
When I want to shut down my robot, issuing a call to the /RobotPower service will do the trick for shutting everything down, BUT it jerks the power out from under the robot's RaspberryPi4. Very often this corrupts my Python logging life.log.

If RobotPower service took a delay: 10 (seconds) parameter, it would give me time to kill my ROS nodes and issue a sudo shutdown -h now on the Pi4.