Zombie Rework (#4060)

# About the pull request

The goal for this PR is to rework zombies into being a fast and
numerous, but weaker, entity. As it stands a zombie has too many
advantages where a hold against them is essentially a fool's errand.

CURRENT PLAN (Will adjust as needed)
Zombies will be FASTER but much weaker than current iteration, with
weaker attacks. They will be designed around being a foe that can be
taken down quicker but if they close the distance, the threat of
infection spells a death sentence.

# Explain why it's good for the game

This will be hard to balance, and as such will be taking feedback before
I submit this for review. This is current position of Zombies:

- Tough: Extreme (25% ?!) brute modifier, with fire modifier on top,
making them very tanky and requiring clips to take down one
- self-revive: They WILL come back up, coupled with toughness, they are
a feared opponent.
- Strength: Claws inflict superslow at 40 brute damage, one of the
highest damage levels.
- Numerous: They have the numbers to put lesser drones and even entire
hives to shame

Overall, they are very overtuned and makes playing against them not that
fun. My plan is to have it so they are much weaker, with their threat
being from infections.

# Testing Photographs and Procedure
<details>
<summary>Screenshots & Videos</summary>

Put screenshots and videos here with an empty line between the
screenshots and the `<details>` tags.

</details>


# Changelog
:cl:
balance: Zombie attacks deal less damage and only slow down targets (not
superslow as they currently do)
balance: Zombie resistances have been reduced heavily, making them far
more susceptible to brute damage. Their speed has been doubled to
compensate
balance: Black goo on tiles now requires you to not wear shoes to have
chance for infection
fix: Zombie attacks now only apply effects such as slow and infection if
the attack is valid (if the zombie is able to attack)
/:cl:

code/datums/diseases/black_goo.dm

@@ -124,7 +124,7 @@
 	icon = 'icons/mob/humans/species/r_zombie.dmi'
 	icon_state = "claw_l"
 	flags_item = NODROP|DELONDROP|ITEM_ABSTRACT
-	force = 40
+	force = MELEE_FORCE_TIER_6 //slightly higher than normal
 	w_class = SIZE_MASSIVE
 	sharp = 1
 	attack_verb = list("slashed", "torn", "scraped", "gashed", "ripped")
@@ -135,8 +135,9 @@
 		return FALSE
 
 	. = ..()
-	if(.)
-		playsound(loc, 'sound/weapons/bladeslice.ogg', 25, 1, 5)
+	if(!.)
+		return FALSE
+	playsound(loc, 'sound/weapons/bladeslice.ogg', 25, 1, 5)
 
 	if(ishuman_strict(target))
 		var/mob/living/carbon/human/human = target
@@ -149,10 +150,7 @@
 				target.AddDisease(new /datum/disease/black_goo)
 				to_chat(user, SPAN_XENOWARNING("<b>You sense your target is now infected.</b>"))
 
-	if(issynth(target))
-		target.apply_effect(2, SLOW)
-	else
-		target.apply_effect(2, SUPERSLOW)
+	target.apply_effect(2, SLOW)
 
 /obj/item/weapon/zombie_claws/afterattack(obj/O as obj, mob/user as mob, proximity)
 	if(get_dist(src, O) > 1)

code/game/objects/effects/decals/cleanable/misc.dm

@@ -169,7 +169,7 @@
 /obj/effect/decal/cleanable/blackgoo/Crossed(mob/living/carbon/human/H)
 	if(!istype(H)) return
 	if(H.species.name == "Human")
-		if(!H.shoes || prob(25))
+		if(!H.shoes && prob(50))
 			H.contract_disease(new /datum/disease/black_goo)
 
 

code/modules/mob/living/carbon/human/species/zombie.dm

@@ -1,8 +1,12 @@
+// DEFINES
+///Time until a zombie rises from the dead
+#define ZOMBIE_REVIVE_TIME 1 MINUTES
+
 /datum/species/zombie
 	group = SPECIES_HUMAN
 	name = SPECIES_ZOMBIE
 	name_plural = "Zombies"
-	slowdown = 1
+	slowdown = 0.75
 	blood_color = BLOOD_COLOR_ZOMBIE
 	icobase = 'icons/mob/humans/species/r_goo_zed.dmi'
 	deform = 'icons/mob/humans/species/r_goo_zed.dmi'
@@ -12,7 +16,7 @@
 	death_message = "seizes up and falls limp..."
 	flags = NO_BREATHE|NO_CLONE_LOSS|NO_POISON|NO_NEURO|NO_SHRAPNEL
 	mob_inherent_traits = list(TRAIT_FOREIGN_BIO)
-	brute_mod = 0.25 //EXTREME BULLET RESISTANCE
+	brute_mod = 0.6 //Minor bullet resistance
 	burn_mod = 0.8 //Lowered burn damage since it would 1-shot zombies from 2 to 0.8.
 	speech_chance  = 5
 	cold_level_1 = -1  //zombies don't mind the cold
@@ -96,7 +100,7 @@
 				zombie.play_screen_text("<span class='langchat' style=font-size:16pt;text-align:center valign='top'><u>You are dead...</u></span><br>You will rise again in one minute.", /atom/movable/screen/text/screen_text/command_order, rgb(155, 0, 200))
 			to_chat(zombie, SPAN_XENOWARNING("You fall... but your body is slowly regenerating itself."))
 			var/weak_ref = WEAKREF(zombie)
-			to_revive[weak_ref] = addtimer(CALLBACK(src, PROC_REF(revive_from_death), zombie, "[REF(zombie)]"), 1 MINUTES, TIMER_STOPPABLE|TIMER_OVERRIDE|TIMER_UNIQUE|TIMER_NO_HASH_WAIT)
+			to_revive[weak_ref] = addtimer(CALLBACK(src, PROC_REF(revive_from_death), zombie, "[REF(zombie)]"), ZOMBIE_REVIVE_TIME, TIMER_STOPPABLE|TIMER_OVERRIDE|TIMER_UNIQUE|TIMER_NO_HASH_WAIT)
 			revive_times[weak_ref] = world.time + 1 MINUTES
 		else
 			if(zombie.client)