Removes bad nodamage var from projectiles, fixes Juggernaut / Rust Walker projectiles doing zero damage (#73806)

## About The Pull Request

- Juggernaut and Rust Walker projectiles were subtyped off of magic,
which is `nodamage`.

- The juggernaut actually had a copy+paste error with their type
`on_hit` which caused none of their special effects on hit ("relative
patching catches this")

- Then I realized projectiles have this var `nodamage` which is, for all
intents and purposes, just `damage > 0`. it's not checked for pacifism,
it's just that. This is dumb. So very dumb, so I removed it.
- There are, however, a few situations which used it in a unique way,
such as the blast wave cannon. This is why I replaced it with a proc,
`is_hostile_projectile`, for certain situations to actually find out if
the projectile is damaging. Projectiles can override this on a per type
basis by default, damaging projectiles = hostile.
- This has a chance to break some things, but I ... kinda doubt it will.

Fixes #73756

## Why It's Good For The Game

Projectiles that act as they should, less dumb vars

## Changelog

🆑 Melbert
fix: Fixes Juggernaut / Rust Walker projectiles doing zero damage
fix: Fixes Juggernaut projectiles not doing bonus damage to nearby
structures
code: Removed projectile nodamage var, replaces it with just checking
for damage
/🆑

code/modules/mining/equipment/kinetic_crusher.dm

@@ -177,7 +177,6 @@
 /obj/projectile/destabilizer
 	name = "destabilizing force"
 	icon_state = "pulse1"
-	nodamage = TRUE
 	damage = 0 //We're just here to mark people. This is still a melee weapon.
 	damage_type = BRUTE
 	armor_flag = BOMB
@@ -304,7 +303,6 @@
 		marker.name = "heated [marker.name]"
 		marker.icon_state = "lava"
 		marker.damage = bonus_value
-		marker.nodamage = FALSE
 		deadly_shot = FALSE
 
 //icewing watcher
@@ -421,7 +419,6 @@
 		marker.name = "deadly [marker.name]"
 		marker.icon_state = "chronobolt"
 		marker.damage = bonus_value
-		marker.nodamage = FALSE
 		marker.speed = 2
 		deadly_shot = FALSE