Wrapping paper fixes. (#73803)

## About The Pull Request

This, as the title suggests, fixes some wrapping paper bugs.

First, wrapping paper coloration has been rebound to Alt+click, so the
control doesn't conflict with extracting wrapping paper from a roll,
which is right click. Originally, both of them were on right click,
which caused problems.

Second, it fixes a problem with the greyscale icons on the gifts
themselves. They were showing up as the default gift icon, no matter
what color you selected, because the automatic path generation wasn't
set up properly. This fixes that.

Fixes #73800.

## Why It's Good For The Game

Bugs are bad, and we should try to fix them.

## Changelog
🆑
fix: Gifts you wrap will now display their greyscale colors as they're
supposed to.
fix: Wrapping paper color selection has been rebound to Alt+click, to
fix a bug where both wrapping paper color selection, and extracting
wrapping paper from a roll were both bound to right click.
/🆑

code/game/objects/items/stacks/wrap.dm

@@ -36,7 +36,7 @@
 		//Set layers to these colors, base then ribbon
 		set_greyscale(colors = list(generated_base_color, generated_ribbon_color))
 
-/obj/item/stack/wrapping_paper/attack_hand_secondary(mob/user, modifiers)
+/obj/item/stack/wrapping_paper/AltClick(mob/user, modifiers)
 	var/new_base = input(user, "", "Select a base color", color) as color
 	var/new_ribbon = input(user, "", "Select a ribbon color", color) as color
 	if(!user.can_perform_action(src))

code/modules/recycling/sortingmachinery.dm

@@ -131,7 +131,7 @@
 		if(wrapping_paper.use(3))
 			user.visible_message(span_notice("[user] wraps the package in festive paper!"))
 			giftwrapped = TRUE
-			greyscale_config = text2path("/datum/greyscale_config/[icon_state]")
+			greyscale_config = text2path("/datum/greyscale_config/gift[icon_state]")
 			set_greyscale(colors = wrapping_paper.greyscale_colors)
 			update_appearance()
 		else