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.Shared/Delivery/SharedDeliverySystem.cs

@@ -12,6 +12,7 @@ using Content.Shared.Tag;
 using Content.Shared.Verbs;
 using Robust.Shared.Audio.Systems;
 using Robust.Shared.Containers;
+using Robust.Shared.Prototypes;
 
 namespace Content.Shared.Delivery;
 
@@ -30,6 +31,9 @@ public abstract class SharedDeliverySystem : EntitySystem
     [Dependency] private readonly SharedHandsSystem _hands = default!;
     [Dependency] private readonly NameModifierSystem _nameModifier = default!;
 
+    private static readonly ProtoId<TagPrototype> TrashTag = "Trash";
+    private static readonly ProtoId<TagPrototype> RecyclableTag = "Recyclable";
+
     public override void Initialize()
     {
         base.Initialize();
@@ -129,7 +133,7 @@ public abstract class SharedDeliverySystem : EntitySystem
         ent.Comp.IsOpened = true;
         _appearance.SetData(ent, DeliveryVisuals.IsTrash, ent.Comp.IsOpened);
 
-        _tag.AddTags(ent, "Trash", "Recyclable");
+        _tag.AddTags(ent, TrashTag, RecyclableTag);
         EnsureComp<SpaceGarbageComponent>(ent);
         RemComp<StealTargetComponent>(ent); // opened mail should not count for the objective