back up ligths no trailer

Simple maybe. quick? Not so much. You will most likely need a second pig tail. I installed a junction box near my tail lights on the truck and pulled the reverse power from there. I run it to the back of the cab and wired it into my aux plug. On the trailer side it's a matter of running the wire back through the trailer to another junction box and splitting from there to the lights.
Things to remember
if your going to run it off of your rev. switch you should use LEDs to keep from burning out your rev switch.
When running wire I use jacketed wire and try to make connections inside a sealed junction box.

 

I've pulled a van trailer before that had reverse lights on it that turned on after backing up about 5ft.

the mega that had this didn't have many like this in its fleet. So I assume it's an option or was one at sometime.

 

All the european trucks and trailers have backup lights, by the law and no problems with those lights. So, yes, can be done.