Refactor modular computer (and application) attackby into item_interaction (#84245)

## About The Pull Request

Sooooooooo I was recently notified of an issue (#84185) that popped up
from me replacing the `attackby(...)` chain on id cards, where it's no
longer possible to put money into IDs inside of PDAs by slapping it
against the PDA.
As I expected, this is because modular computers both still use
`attackby(...)`, and would call `attackby(...)` on the ID they contained
if hit with cash.

https://github.com/tgstation/tgstation/blob/24a23009e8ee4d056b6671c70c41feab1a18590b/code/modules/modular_computers/computers/item/computer.dm#L799
Now this could've been an easy one line no-gbp fix where I just replace
it with a direct call to `insert_money(...)` on the ID and call it a
day!
But hey. Might as well get rid of the `attackby(...)` altogether while
we're at it.


First off, because the `attackby(...)` proc was getting quite bloated,
we split off all the specific item behaviours into `[X]_act(...)` type
procs to clean it up.
We then make those return item interaction flags, so we can call them on
`item_interaction(...)` after the right typecheck passes and immediately
return their results.
This also involves replacing the `application_attackby(...)` on
applications with an `application_item_interaction(...)`, and making it
return the item interaction flags too.

The code of each subsection isn't significantly different, though
reorganized a bit in some cases.
Like inserting a computer disks now tries to move it into the computer
_first_ before swapping out whichever disk is already in there, so it
doesn't swap out the disk if putting the new one in fails.
## Why It's Good For The Game

Fixes #84185.
Having more stuff be updated to the proper `item_interaction(...)`
system is cool and good.

code/modules/modular_computers/file_system/computer_file.dm

@@ -66,9 +66,9 @@
 /datum/computer_file/proc/on_examine(obj/item/modular_computer/source, mob/user)
 	return null
 
-/// Called when attacking a tablet with an item, checking if any application uses it. Return TRUE to cancel the attack chain.
-/datum/computer_file/proc/application_attackby(obj/item/attacking_item, mob/living/user)
-	return FALSE
+/// Called on modular computer item_interaction, checking if any application uses the given item. Uses the item interaction chain flags.
+/datum/computer_file/proc/application_item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	return NONE
 
 /**
  * Implement this when your program has an object that the user can eject.