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/programs/airestorer.dm

@@ -57,22 +57,22 @@
 
 	return TRUE
 
-/datum/computer_file/program/ai_restorer/application_attackby(obj/item/attacking_item, mob/living/user)
+/datum/computer_file/program/ai_restorer/application_item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/aicard))
+		return aicard_act(user, tool)
+
+/datum/computer_file/program/ai_restorer/proc/aicard_act(mob/living/user, obj/item/aicard/used_aicard)
 	if(!computer)
-		return FALSE
-	if(!istype(attacking_item, /obj/item/aicard))
-		return FALSE
-
+		return NONE
 	if(stored_card)
-		to_chat(user, span_warning("You try to insert \the [attacking_item] into \the [computer.name], but the slot is occupied."))
-		return FALSE
-	if(user && !user.transferItemToLoc(attacking_item, computer))
-		return FALSE
+		to_chat(user, span_warning("You try to insert \the [used_aicard] into \the [computer.name], but the slot is occupied."))
+		return ITEM_INTERACT_BLOCKING
+	if(!user.transferItemToLoc(used_aicard, computer))
+		return ITEM_INTERACT_BLOCKING
 
-	stored_card = attacking_item
-	to_chat(user, span_notice("You insert \the [attacking_item] into \the [computer.name]."))
-
-	return TRUE
+	stored_card = used_aicard
+	to_chat(user, span_notice("You insert \the [used_aicard] into \the [computer.name]."))
+	return ITEM_INTERACT_SUCCESS
 
 /datum/computer_file/program/ai_restorer/try_eject(mob/living/user, forced = FALSE)
 	if(!stored_card)

code/modules/modular_computers/file_system/programs/frontier.dm

@@ -24,13 +24,16 @@
 	if(!CONFIG_GET(flag/no_default_techweb_link) && !linked_techweb)
 		CONNECT_TO_RND_SERVER_ROUNDSTART(linked_techweb, computer)
 
-/datum/computer_file/program/scipaper_program/application_attackby(obj/item/attacking_item, mob/living/user)
-	if(!istype(attacking_item, /obj/item/multitool))
-		return FALSE
-	var/obj/item/multitool/attacking_tool = attacking_item
-	if(!QDELETED(attacking_tool.buffer) && istype(attacking_tool.buffer, /datum/techweb))
-		linked_techweb = attacking_tool.buffer
-	return TRUE
+/datum/computer_file/program/scipaper_program/application_item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/multitool))
+		return multitool_act(user, tool)
+
+/datum/computer_file/program/scipaper_program/proc/multitool_act(mob/living/user, obj/item/multitool/used_multitool)
+	if(QDELETED(used_multitool.buffer) || !istype(used_multitool.buffer, /datum/techweb))
+		return ITEM_INTERACT_BLOCKING
+	linked_techweb = used_multitool.buffer
+	computer.balloon_alert(user, "buffer linked!")
+	return ITEM_INTERACT_SUCCESS
 
 /datum/computer_file/program/scipaper_program/proc/recheck_file_presence()
 	if(selected_file in computer.get_files(include_disk_files = TRUE))

code/modules/modular_computers/file_system/programs/maintenance/modsuit.dm

@@ -17,12 +17,10 @@
 		unsync_modsuit()
 	return ..()
 
-/datum/computer_file/program/maintenance/modsuit_control/application_attackby(obj/item/attacking_item, mob/living/user)
-	. = ..()
-	if(!istype(attacking_item, /obj/item/mod/control))
-		return FALSE
-	sync_modsuit(attacking_item, user)
-	return TRUE
+/datum/computer_file/program/maintenance/modsuit_control/application_item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/mod/control))
+		sync_modsuit(tool, user)
+		return ITEM_INTERACT_SUCCESS
 
 /datum/computer_file/program/maintenance/modsuit_control/proc/sync_modsuit(obj/item/mod/control/new_modsuit, mob/living/user)
 	if(controlled_suit)

code/modules/modular_computers/file_system/programs/techweb.dm

@@ -26,13 +26,16 @@
 	if(!CONFIG_GET(flag/no_default_techweb_link) && !stored_research)
 		CONNECT_TO_RND_SERVER_ROUNDSTART(stored_research, computer)
 
-/datum/computer_file/program/science/application_attackby(obj/item/attacking_item, mob/living/user)
-	if(!istype(attacking_item, /obj/item/multitool))
-		return FALSE
-	var/obj/item/multitool/attacking_tool = attacking_item
-	if(!QDELETED(attacking_tool.buffer) && istype(attacking_tool.buffer, /datum/techweb))
-		stored_research = attacking_tool.buffer
-	return TRUE
+/datum/computer_file/program/science/application_item_interaction(mob/living/user, obj/item/tool, list/modifiers)
+	if(istype(tool, /obj/item/multitool))
+		return multitool_act(user, tool)
+
+/datum/computer_file/program/science/proc/multitool_act(mob/living/user, obj/item/multitool/used_multitool)
+	if(QDELETED(used_multitool.buffer) || !istype(used_multitool.buffer, /datum/techweb))
+		return ITEM_INTERACT_BLOCKING
+	stored_research = used_multitool.buffer
+	computer.balloon_alert(user, "buffer linked!")
+	return ITEM_INTERACT_SUCCESS
 
 /datum/computer_file/program/science/ui_assets(mob/user)
 	return list(