Revert 'Revert 'Solution Entities'' (#23168)

Content.Shared/Chemistry/Components/SmokeComponent.cs

@@ -13,6 +13,12 @@ public sealed partial class SmokeComponent : Component
 {
     public const string SolutionName = "solutionArea";
 
+    /// <summary>
+    /// The solution on the entity with touch and ingestion reactions.
+    /// </summary>
+    [DataField]
+    public Entity<SolutionComponent>? Solution = null;
+
     /// <summary>
     /// The max amount of tiles this smoke cloud can spread to.
     /// </summary>