Move entity effects definitions to shared (#35614)

* Move entity effects to shared

* relocate spawning to server

* Generic version of EntityEffect for just raising event.

* genericise everything

* oops forgot to push you

* some condensation

* finish rebas

* unwhite the space

* oops forgot nuke

* bad rebase fix

* useless annotations begone

---------

Co-authored-by: EmoGarbage404 <retron404@gmail.com>

Content.Shared/EntityEffects/Effects/ModifyLungGas.cs

@@ -0,0 +1,14 @@
+using Content.Shared.Atmos;
+using Robust.Shared.Prototypes;
+
+namespace Content.Shared.EntityEffects.Effects;
+
+public sealed partial class ModifyLungGas : EventEntityEffect<ModifyLungGas>
+{
+    [DataField("ratios", required: true)]
+    public Dictionary<Gas, float> Ratios = default!;
+
+    // JUSTIFICATION: This is internal magic that players never directly interact with.
+    protected override string? ReagentEffectGuidebookText(IPrototypeManager prototype, IEntitySystemManager entSys)
+        => null;
+}