Improves the JobSpecial system. (#4626)

* Improves the JobSpecial system.

* clean up code

Content.Shared/Roles/JobPrototype.cs

@@ -50,8 +50,8 @@ namespace Content.Shared.Roles
 
         [DataField("icon")] public string Icon { get; } = string.Empty;
 
-        [DataField("special")]
-        public JobSpecial? Special { get; private set; }
+        [DataField("special", serverOnly:true)]
+        public JobSpecial[] Special { get; private set; } = Array.Empty<JobSpecial>();
 
         [DataField("departments")]
         public IReadOnlyCollection<string> Departments { get; } = Array.Empty<string>();

Content.Shared/Roles/JobSpecial.cs

@@ -9,9 +9,6 @@ namespace Content.Shared.Roles
     [ImplicitDataDefinitionForInheritors]
     public abstract class JobSpecial
     {
-        public virtual void AfterEquip(IEntity mob)
-        {
-
-        }
+        public abstract void AfterEquip(IEntity mob);
     }
 }