Fire extinguisher safety (#4912)

* Moved safety into FireExtinguisherComponent.

* Fix errant find and replace

* Address reviews

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Shared/Extinguisher/SharedFireExtinguisherComponent.cs

@@ -0,0 +1,17 @@
+using System;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.Extinguisher
+{
+    public abstract class SharedFireExtinguisherComponent : Component
+    {
+        public override string Name => "FireExtinguisher";
+    }
+
+    [Serializable, NetSerializable]
+    public enum FireExtinguisherVisuals : byte
+    {
+        Safety
+    }
+}