Extracts magic strings from Tag calls (#36305)

* Extracts magic strings from Tag calls

When #36281 gets merged, the `TagSystem` methods will all give warnings. Let's fix those warnings before they even happen!

* Adds missing libraries

* Remove not yet implemented TagSystem changes

* Fix tag spelling error

Genuinely surprised there was only 1!

* Styling and proper type changes

* Styling

Co-authored-by: Tayrtahn <tayrtahn@gmail.com>

---------

Co-authored-by: Tayrtahn <tayrtahn@gmail.com>

Content.Server/Light/EntitySystems/ExpendableLightSystem.cs

@@ -10,6 +10,7 @@ using Content.Shared.Verbs;
 using JetBrains.Annotations;
 using Robust.Server.GameObjects;
 using Robust.Shared.Audio.Systems;
+using Robust.Shared.Prototypes;
 using Robust.Shared.Utility;
 
 namespace Content.Server.Light.EntitySystems
@@ -24,6 +25,8 @@ namespace Content.Server.Light.EntitySystems
         [Dependency] private readonly SharedAppearanceSystem _appearance = default!;
         [Dependency] private readonly MetaDataSystem _metaData = default!;
 
+        private static readonly ProtoId<TagPrototype> TrashTag = "Trash";
+
         public override void Initialize()
         {
             base.Initialize();
@@ -69,7 +72,7 @@ namespace Content.Server.Light.EntitySystems
                         _metaData.SetEntityName(ent, Loc.GetString(component.SpentName), meta);
                         _metaData.SetEntityDescription(ent, Loc.GetString(component.SpentDesc), meta);
 
-                        _tagSystem.AddTag(ent, "Trash");
+                        _tagSystem.AddTag(ent, TrashTag);
 
                         UpdateSounds(ent);
                         UpdateVisualizer(ent);