Fixes playing cards (#5337)

# About the pull request

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3 layers of fixes for a pretty bad bug with playing cards you might have
seen recently.


# Changelog
:cl:
fix: Fixed an exploit involving playing cards.
/:cl:

code/game/objects/items/toys/cards.dm

@@ -30,6 +30,10 @@
 	. = ..()
 	populate_deck()
 
+/obj/item/toy/deck/Destroy(force)
+	. = ..()
+	QDEL_NULL_LIST(cards)
+
 /obj/item/toy/deck/get_examine_text(mob/user)
 	. = ..()
 	. += SPAN_NOTICE("There are <b>[length(cards)]</b> cards remaining in the deck.")
@@ -75,6 +79,7 @@
 		var/obj/item/toy/handcard/H = O
 		for(var/datum/playing_card/P as anything in H.cards)
 			cards += P
+			H.cards -= P
 		update_icon()
 		qdel(O)
 		user.visible_message(SPAN_NOTICE("<b>[user]</b> places their cards on the bottom of \the [src]."), SPAN_NOTICE("You place your cards on the bottom of the deck."))
@@ -271,6 +276,10 @@
 	if(!concealed)
 		. += " ([length(cards)] card\s)"
 
+/obj/item/toy/handcard/Destroy(force)
+	. = ..()
+	QDEL_NULL_LIST(cards)
+
 /obj/item/toy/handcard/aceofspades
 	icon_state = "spades_ace"
 	desc = "An Ace of Spades"
@@ -315,6 +324,9 @@
 
 	//fuck any qsorts and merge sorts. This needs to be brutally easy
 	var/cards_length = length(cards)
+	if(cards_length >= 200)
+		to_chat(usr, SPAN_WARNING("Your hand is too big to sort. Remove some cards."))
+		return
 	for(var/i = 1 to cards_length)
 		for(var/k = 2 to cards_length)
 			if(cards[i].sort_index > cards[k].sort_index)
@@ -331,6 +343,7 @@
 		var/cards_length = length(H.cards)
 		for(var/datum/playing_card/P in H.cards)
 			cards += P
+			H.cards -= P
 		qdel(O)
 		if(pile_state)
 			if(concealed)
@@ -390,6 +403,8 @@
 /obj/item/toy/handcard/MouseDrop(atom/over)
 	if(usr != over || !Adjacent(usr))
 		return
+	if(ismob(loc))
+		return
 	usr.put_in_hands(src)
 
 /obj/item/toy/handcard/get_examine_text(mob/user)
@@ -423,6 +438,12 @@
 			name = "a playing card"
 			desc = "A playing card."
 
+	if(length(cards) >= 200)
+		// BYOND will flat out choke when using thousands of cards for some unknown reason,
+		// possibly due to the transformed overlay stacking below. Nobody's gonna see the
+		// difference past 40 or so anyway.
+		return
+
 	overlays.Cut()
 
 	if(!cards_length)