Allow for placing certain items directly on the floor, with precision (#90805)

## About The Pull Request

So I really wanted to do the stereotypical "really I'm just a
construction worker" break-in bit, but then quickly realized you can't
even place warning cones on the floor! You have to awkwardly drop them,
or put them on a table and move them off!
Thinking about that, I remembered my similar annoyance with candles for
rituals or wet floor signs when playing a janitor.

Initially this was intended to include the ability to stack warning
cones for easy storage and placement, but I realized that was taking a
_lot_ more time than making the other items placeable on the floor.
Because of this, I decided to atomize the much less complex part off
into this pr.

So here, in this pr, we add a simple element
`/datum/element/floor_placeable` and apply it to a list of items for
which I think "placing it on the floor" makes enough sense as an
interaction.

As a side to this, we add the plastic pickup/drop noises to wet floor
signs and warning cones, because they're made of plastic and it's
leagues better than being entirely inaudible.
We remove `var/cooldown = 0` from `/obj/item/toy/cattoy` because it
wasn't used.
## Why It's Good For The Game

Can't do the stereotypical hazard vest break-in in _style_ without the
ability to actually place the cones:

![image](https://github.com/user-attachments/assets/d9e8707b-87a2-4463-8bac-a5d8adf917c7)

Oh man is it so much less of a pain to make fancy schmancy rituals when
you don't have to place candles on tables and drag them off for it to
work:

![image](https://github.com/user-attachments/assets/c8d4966e-29b8-48bc-ac0b-c357157d4ba3)

It's really funny to be able to play with toys on the floor:

![image](https://github.com/user-attachments/assets/d604157e-4a90-4e50-a44f-0e9f2f63aeac)
## Changelog
🆑
add: Certain items can now be placed directly on the floor in the
clicked on location. This currently includes warning cones, wet floor
signs, candles, action figures, plushies, mech toys, and a list of other
toys.
sound: Warning cones now use plastic pickup/drop sounds.
sound: Wet floor signs now use plastic pickup/drop sounds.
/🆑

code/game/objects/items/trash.dm

@@ -115,6 +115,10 @@
 	icon_state = "candle4"
 	custom_materials = null
 
+/obj/item/trash/candle/Initialize(mapload)
+	. = ..()
+	AddElement(/datum/element/floor_placeable)
+
 /obj/item/trash/flare
 	name = "burnt flare"
 	icon = 'icons/obj/lighting.dmi'