Relay stamped cmd vel

[garyservin]

🦟 Bug fix

Fixes #281

Summary

This remaps the diff_drive controller velocity command input to /cmd_vel_stamped and adds a relay node that transforms any message received in the /cmd_vel topic (unstamped) and stamps a header to it and republishes to /cmd_vel_stamped. This also changes the keyboard and joystick teleop nodes to use stamped messages and send them directly to the /cmd_vel_stamped topic

Checklist

• Signed all commits for DCO
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[francocipollone]

Thanks for the contribution @garyservin as always! This will be important mainly as Nav2 is switching its default to stamped Twist! Thanks!