Mouse drag & drop refactored attack chain (#83690)

## About The Pull Request
Mouse drag & drop has been refactored into its own attack chain. The
flowchart below summarizes it

![Flowchart](https://github.com/tgstation/tgstation/assets/110812394/d92047ff-d94c-44a6-9e87-354c3d525021)

Brief summary of each proc is as follows

**1. `atom/MouseDrop()`**
- It is now non overridable. No subtype should ever touch this proc
because it performs 2 basic checks
  
a) Measures the time between mouse down & mouse release. If its less
than `LENIENCY_TIME`(0.1 seconds) then the operation is not considered a
drag but a simple click

b) Measures the distance squared between the drag start & end point. If
its less than `LENIENCY_DISTANCE`(16 pixels screen space) then the drag
is considered too small and is discarded

- These 2 sanity checks for drag & drop are applied across all
operations without fail
  
**2. `atom/base_mouse_drop_handler()`**
- This is where atoms handle mouse drag & drop inside the world. Ideally
it is non overridable in most cases because it also performs 2 checks
- Is the dragged object & the drop target adjacent to the player?.
Screen elements always return true for this case
  
- Additional checks can be enforced by `can_perform_action()` done only
on the dragged object. It uses the combined flags of
`interaction_flags_mouse_drop` for both the dragged object & drop target
to determine if the operation is feasible.
     
We do this only on the dragged object because if both the dragged object
& drop target are adjacent to the player then `can_perform_action()`
will return the same results when done on either object so it makes no
difference.

Checks can be bypassed via the `IGNORE_MOUSE_DROP_CHECKS` which is used
by huds & screen elements or in case you want to implement your own
unique checks

**3. `atom/mouse_drop_dragged()`**
- Called on the object that is being dragged, drop target passed here as
well, subtypes do their stuff here
- `COMSIG_MOUSEDROP_ONTO` is sent afterwards. It does not require
subtypes to call their parent proc

**4. `atom/mouse_drop_receive()`**
- Called on the drop target that is receiving the dragged object,
subtypes do their stuff here
- `COMSIG_MOUSEDROPPED_ONTO` is sent afterwards. It does not require
subtypes to call their parent proc

## Why It's Good For The Game
Implements basic sanity checks across all drag & drop operations. Allows
us to reduce code like this


https://github.com/tgstation/tgstation/blob/8c8311e624271a6f6decba8cd643b33b9904534a/code/game/machinery/dna_scanner.dm#L144-L145

Into this

```
if(!iscarbon(target))
	return
```

I'm tired of seeing this code pattern `!Adjacent(user) ||
!user.Adjacent(target)` copy pasted all over the place. Let's just write
that at the atom level & be done with it

## Changelog
🆑
refactor: Mouse drag & drop attack chain has been refactored. Report any
bugs on GitHub
fix: You cannot close the cryo tube on yourself with Alt click like
before
/🆑

---------

Co-authored-by: MrMelbert <51863163+MrMelbert@users.noreply.github.com>
Co-authored-by: Bloop <13398309+vinylspiders@users.noreply.github.com>

code/modules/modular_computers/computers/item/computer.dm

@@ -12,6 +12,7 @@
 	max_integrity = 100
 	armor_type = /datum/armor/item_modular_computer
 	light_system = OVERLAY_LIGHT_DIRECTIONAL
+	interaction_flags_mouse_drop = NEED_HANDS | ALLOW_RESTING
 
 	///The ID currently stored in the computer.
 	var/obj/item/card/id/computer_id_slot
@@ -334,11 +335,9 @@
 	update_appearance()
 	return TRUE
 
-/obj/item/modular_computer/MouseDrop(obj/over_object, src_location, over_location)
-	var/mob/M = usr
-	if((!istype(over_object, /atom/movable/screen)) && usr.can_perform_action(src))
-		return attack_self(M)
-	return ..()
+/obj/item/modular_computer/mouse_drop_dragged(atom/over_object, mob/user)
+	if(!istype(over_object, /atom/movable/screen))
+		return attack_self(user)
 
 /obj/item/modular_computer/attack_ai(mob/user)
 	return attack_self(user)

code/modules/modular_computers/computers/item/laptop.dm

@@ -11,6 +11,8 @@
 	hardware_flag = PROGRAM_LAPTOP
 	max_idle_programs = 3
 	w_class = WEIGHT_CLASS_NORMAL
+	interaction_flags_mouse_drop = NEED_HANDS
+
 
 	// No running around with open laptops in hands.
 	item_flags = SLOWS_WHILE_IN_HAND
@@ -58,20 +60,15 @@
 
 	try_toggle_open(usr)
 
-/obj/item/modular_computer/laptop/MouseDrop(obj/over_object, src_location, over_location)
-	. = ..()
-	if(over_object == usr || over_object == src)
-		try_toggle_open(usr)
+/obj/item/modular_computer/laptop/mouse_drop_dragged(atom/over_object, mob/user, src_location, over_location, params)
+	if(over_object == user || over_object == src)
+		try_toggle_open(user)
 		return
 	if(istype(over_object, /atom/movable/screen/inventory/hand))
 		var/atom/movable/screen/inventory/hand/H = over_object
-		var/mob/M = usr
-
-		if(M.stat != CONSCIOUS || HAS_TRAIT(M, TRAIT_HANDS_BLOCKED))
+		if(!isturf(loc))
 			return
-		if(!isturf(loc) || !Adjacent(M))
-			return
-		M.put_in_hand(src, H.held_index)
+		user.put_in_hand(src, H.held_index)
 
 /obj/item/modular_computer/laptop/attack_hand(mob/user, list/modifiers)
 	. = ..()