Mob attackedby / check_block refactor, plus some minor cleanup of attack_x procs (#79563)

## About The Pull Request

- Deletes `spec_attacked_by`
- Elements simple/basic mob attack threshold
- There was a skeleton mob that "mimics armor" but didn't use the actual
mimicing armor thing we have, so I changed that.
- Moves `check_shields` down to the living level, renames it to
`check_block`
 - Martial art blocking is now signalized (only CQC uses it anyways) 
- Cleaned up a bit of `attack_x` procs, but not a lot. Should have an
entire PR dedicated to this .... mess.
 - Deprecates `/obj/item/melee`

## Why It's Good For The Game

Second verse, same as the first. 

- Less bad species related procs. 
- Largely brings a lot of code in line, making combat more consistent
across types.
- Makes it a lot easier to add new code relating to blocking or taking
damage.

## Changelog

🆑 Melbert
refactor: Refactored another large chuck of attack code, primarily
involving melee item attacks and non-human mob attacks. Report if you
see anything weird
fix: Pacifists clicking on simple robots or silicons no longer causes
sparks
fix: Blocked thrown batons are now properly... blocked
/🆑

code/modules/mob/living/basic/cult/constructs/juggernaut.dm

@@ -17,7 +17,6 @@
 	attack_sound = 'sound/weapons/punch3.ogg'
 	status_flags = NONE
 	mob_size = MOB_SIZE_LARGE
-	force_threshold = 10
 	construct_spells = list(
 		/datum/action/cooldown/spell/basic_projectile/juggernaut,
 		/datum/action/cooldown/spell/forcewall/cult,
@@ -27,6 +26,10 @@
 
 	smashes_walls = TRUE
 
+/mob/living/basic/construct/juggernaut/Initialize(mapload)
+	. = ..()
+	AddElement(/datum/element/damage_threshold, 10)
+
 /// Hostile NPC version. Pretty dumb, just attacks whoever is near.
 /mob/living/basic/construct/juggernaut/hostile
 	ai_controller = /datum/ai_controller/basic_controller/juggernaut