Acid rework

[ubertpendragon]

Acid items are universally considered bad.

• All the acid damage is offloaded onto talents (+65%). This means acid damage is only good if you're a medic with specific talents (What a Stench)
• The acid clouds from acid grenades are excessively small and short in duration. The grenade cannot be used for area denial.
• You need MULTIPLE europabrew to inflict maximum acid vulnerability (enemies resist it since it's a poison), which makes Europabrew pointless to use.
• Advanced syringe gun handling is bad, assuming you should be using this for Europabrew + Acid you cannot use hotkeys to quickly insert an europabrew syringe since it will insert the entire stack (and you will only be shooting brews)

Changes:

Both in balance and functionality:
-Removed bonus acid/poison damage from What a Stench (rebalanced acid damage)
-Advanced syringe gun changed from 8/8 slots to 8/1 slot. This is less slots BUT allows inserting a single syringe (europabrew, morphine) with hotkeys easily which makes it much better to handle. Added a small light.
-Added slow to Europabrew
-Significantly increased Europabrew debuff value (now guarantees 100% acid vulnerability on medium sized creatures in one shot)
-Acid emitter radius increased, slows and gives incrementalstun
-Acid emitters can be "detonated" using fire/explosions, causes a chain reaction
-Various changes to acid/40mm grenades: new inventorysprite, buoyancy, explosion, impact...

I'm eyeballing the balance but the items should be more functional

Explosive gas clouds:
https://github.com/FakeFishGames/Barotrauma/assets/73229309/6ca2b490-d576-4cbd-9b5c-4cba2146ede0