This is an external mod run though the program called https://autohotkey.com/. what is does is make it so one can write a script, in this case the modder made one for FO4 that makes it so that if you were to say press the + key on your number pad, it puts and enters the line "Modpos z 5" when you have the console open. What it does is basically hot key the modpos console commands to your numberpad. So instead of having to manually type out "modpos y -50" or something like that to move a selected item, it's bound to a single key stroke (or 10 technically because it by default moves an item by units of 5). But still way faster than typing it out.
The mod itself isn't actually a FO4 mod at all, it's script for the program above. That's why it's a manual download. As far as I can tell, Autohotkey has noting sketchy going on like adware or annoying secondary programs. If you are comfortable with getting it, get it, and download the mod. Find it in your downloads and place the file: Fallout4_move.ahk anywhere you like, in a folder, on your desktop, and all you have to do is double click it to run the program.
EDIT: Also be wary you can move non player placed items too such as NPC's, boulders, cars, pre-placed houses etc... My strategy around that is A) Make multiples saves often. B )Click on any objects you DON'T want to move such as the house I was building inside of so I can see it's ID, and thus know if I clicked on the wrong thing so you don't accidently raise the walls in the castle by an inch or something.