Repairbots (#86084)

## About The Pull Request
adds repairbots to the game!

![repairbot](https://github.com/user-attachments/assets/8c492c7c-6c12-4095-89f6-cc97ae1edbc0)

this pr serves as a massive rework and buff to floorbots. i was a bit
sad that they dont get built much anymore so ive given them tons of more
utilities and uses.
Repairbots still inherit to place tiles and repair breaches. but they
can now rebuild walls, rebuild windows and repair structure and
machinery. Also Ive given them voicelines to add more character to them.
In short, they are very depressed with their job (however they express
their happy go lucky attitude when u emag them where they will start
deconstructing the station)

to demonstrate capabilities, here's a slightly sped up clip of some
repairbots patching up an area that was maxcapped 4 times:

https://github.com/user-attachments/assets/bddac3b0-1984-4571-85d3-c5283dd7c0de

When repairbots feel threatened, they will retract into their little
toolbox which u can pick up and hold in ur hand, either to conveniently
carry and plop them down at breached sites, or to bash skull with it

U can build them using a toolbox, proximity sensor, cyborg arm and a
conveyor belt

## Why It's Good For The Game
refactors floorbots and makes them alot more useful tools for engineers
to use


## Changelog
🆑
refactor: floorbots have been refactored, please report any bugs
add: adds repairbots to the game!
/🆑

code/game/objects/items/stacks/stack.dm

@@ -591,7 +591,7 @@
 		return FALSE
 	if(is_cyborg) // No merging cyborg stacks into other stacks
 		return FALSE
-	if(ismob(loc) && !inhand) // no merging with items that are on the mob
+	if(ismob(loc) && !inhand && !HAS_TRAIT(loc, TRAIT_MOB_MERGE_STACKS)) // no merging with items that are on the mob
 		return FALSE
 	if(istype(loc, /obj/machinery)) // no merging items in machines that aren't both in componentparts
 		var/obj/machinery/machine = loc