Improves the JobSpecial system. (#4626)

* Improves the JobSpecial system.

* clean up code

Content.Server/Jobs/AddComponentSpecial.cs

@@ -0,0 +1,26 @@
+using Content.Server.Interaction.Components;
+using Content.Shared.Roles;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Serialization.Manager.Attributes;
+
+namespace Content.Server.Jobs
+{
+    [UsedImplicitly]
+    public sealed class AddComponentSpecial : JobSpecial
+    {
+        // TODO: Type serializer that ensures the component exists.
+        [DataField("component", required:true)]
+        public string Component { get; } = string.Empty;
+
+        public override void AfterEquip(IEntity mob)
+        {
+            // Yes, this will throw if your component is invalid.
+            var component = (Component)IoCManager.Resolve<IComponentFactory>().GetComponent(Component);
+            component.Owner = mob;
+
+            IoCManager.Resolve<IComponentManager>().AddComponent(mob, component);
+        }
+    }
+}