Revert "Revert "epic Respiration Rework"" (#6527)

Content.Server/Chemistry/ReagentEffects/ModifyLungGas.cs

@@ -0,0 +1,24 @@
+using System.Collections.Generic;
+using Content.Server.Body.Components;
+using Content.Shared.Atmos;
+using Content.Shared.Chemistry.Reagent;
+using Robust.Shared.Serialization.Manager.Attributes;
+
+namespace Content.Server.Chemistry.ReagentEffects;
+
+public class ModifyLungGas : ReagentEffect
+{
+    [DataField("ratios", required: true)]
+    private Dictionary<Gas, float> _ratios = default!;
+
+    public override void Effect(ReagentEffectArgs args)
+    {
+        if (args.EntityManager.TryGetComponent<LungComponent>(args.OrganEntity, out var lung))
+        {
+            foreach (var (gas, ratio) in _ratios)
+            {
+                lung.Air.Moles[(int) gas] += (ratio * args.Quantity.Float()) / Atmospherics.BreathMolesToReagentMultiplier;
+            }
+        }
+    }
+}