Unit test material checks are now performed on all crafting recipes by default. All stack recipes now transfer mats to the results (#92620)

## About The Pull Request
Extends the part of the crafting unit test that ensures consistency
between the total mats of the components of a recipe (or rather, the
result of said recipe) and a generic instance of the same type as its
result, previously only implemented on food recipes.

## Why It's Good For The Game
This ensures a degree of consistency with the material composition of
various objects in the game. I couldn't do it in the original PR as that
one was too big already and it took months to get it merged, and have
the relative bugs fixed.

Currently a WIP as I slowly deal with the unit test reports.

## Changelog

🆑
refactor: Follow-up to the crafting/material refactor from months ago.
All objects crafted with stacks now inherit their mat composition (not
necessarily the effects and color) by default, while previously only a
few things like chair, sinks and toilets did. Report any object looking
or behaving weirdly as a result.
fix: The material composition of ammo boxes is no longer a 1/10 of what
it's supposed to be. It was a shitty hack to make it harder to recycle
empty ammo boxes. Instead, they lose materials as they're emptied now.
/🆑

code/game/objects/structures/platform.dm

@@ -18,6 +18,7 @@
 	anchored = TRUE
 	armor_type = /datum/armor/half_wall
 	material_flags = MATERIAL_EFFECTS | MATERIAL_AFFECT_STATISTICS
+	custom_materials = list(/datum/material/iron = PLATFORM_BASE_MATERIAL_AMOUNT)
 	/// Icon used for the frame
 	var/frame_icon = 'icons/obj/smooth_structures/platform/frame_faces/window_frame_normal.dmi'
 	/// Material used in our construction