Pixel adjustments to mobs are now sourced / Refactors riding (#89320)

Fixes #85980

- Pixel adjustments are now sourced

When tweaking a mob's pixel w, x, y, z, is is now done via `add_offsets`
and must have a source string associated

- Refactors riding

Refactors how riding component selects the offsets to use. It's now all
done via the getter rather than a weird mix of a var, a cache, and a
getter.

- Moves a bunch of animations to use `pixel_w` / `pixel_z`

Largely to prevent conflicts with adjustments to a mob's pixel position,
but also as many animations are not actual movements, but visual
movements. Floating is one such example.

It just works

🆑 Melbert
fix: Fixed grab offsets not showing for anything but passive grab
fix: Fix jank with mob offsets when riding things
refactor: Refactored riding component, particularly how it selects layer
and offsets. Report any oddities
refactor: Refactored pixel offsets of mobs. Report any oddities
/🆑

code/modules/mod/modules/modules_supply.dm

@@ -493,8 +493,7 @@
 	mod.wearer.add_filter("mod_ball", 1, alpha_mask_filter(icon = icon('icons/mob/clothing/modsuit/mod_modules.dmi', "ball_mask"), flags = MASK_INVERSE))
 	mod.wearer.add_filter("mod_blur", 2, angular_blur_filter(size = 15))
 	mod.wearer.add_filter("mod_outline", 3, outline_filter(color = "#000000AA"))
-	mod.wearer.base_pixel_y -= 4
-	animate(mod.wearer, animate_time, pixel_y = mod.wearer.base_pixel_y, flags = ANIMATION_PARALLEL)
+	mod.wearer.add_offsets(REF(src), y_add = -4)
 	mod.wearer.SpinAnimation(1.5)
 	mod.wearer.add_traits(user_traits, REF(src))
 	mod.wearer.RemoveElement(/datum/element/footstep, FOOTSTEP_MOB_HUMAN, 1, -6)
@@ -506,8 +505,7 @@
 /obj/item/mod/module/sphere_transform/on_deactivation(display_message = TRUE, deleting = FALSE)
 	if(!deleting)
 		playsound(src, 'sound/items/modsuit/ballin.ogg', 100, TRUE, frequency = -1)
-	mod.wearer.base_pixel_y += 4
-	animate(mod.wearer, animate_time, pixel_y = mod.wearer.base_pixel_y)
+	mod.wearer.remove_offsets(REF(src))
 	addtimer(CALLBACK(mod.wearer, TYPE_PROC_REF(/datum, remove_filter), list("mod_ball", "mod_blur", "mod_outline")), animate_time)
 	mod.wearer.remove_traits(user_traits, REF(src))
 	mod.wearer.remove_movespeed_mod_immunities(REF(src), /datum/movespeed_modifier/damage_slowdown)