Add Smoke and Foam chemical reaction effects. (#2913)

* Adds smoke reaction effect

* smoke tweaks

* address reviews

* Smoke fix

* Refactor smoke and add foam

* Fix stuff

* Remove thing

* Little things

* Address some comments

* Address more things

* More addressing

* License stuff

* Address refactor request

* Small things

* Add nullability

* Update Content.Server/GameObjects/EntitySystems/SolutionAreaEffectSystem.cs

Co-authored-by: Paul Ritter <ritter.paul1@googlemail.com>

Content.Shared/GameObjects/Components/Chemistry/FoamVisuals.cs

@@ -0,0 +1,13 @@
+#nullable enable
+using System;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Chemistry
+{
+    [Serializable, NetSerializable]
+    public enum FoamVisuals : byte
+    {
+        State,
+        Color
+    }
+}

Content.Shared/GameObjects/Components/Chemistry/SmokeVisuals.cs

@@ -0,0 +1,12 @@
+#nullable enable
+using System;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.GameObjects.Components.Chemistry
+{
+    [Serializable, NetSerializable]
+    public enum SmokeVisuals : byte
+    {
+        Color
+    }
+}