Adds portable flasher (#4523)

Co-authored-by: Paul Ritter <ritter.paul1@googlemail.com>
Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>
Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Content.Shared/Trigger/TriggerVisuals.cs

@@ -1,18 +1,29 @@
-using System;
-using Robust.Shared.Serialization;
+using Robust.Shared.Serialization;
 
 namespace Content.Shared.Trigger
 {
-    [NetSerializable]
-    [Serializable]
-    public enum TriggerVisuals
+    [Serializable, NetSerializable]
+    public enum ProximityTriggerVisuals : byte
+    {
+        Off,
+        Inactive,
+        Active,
+    }
+
+    [Serializable, NetSerializable]
+    public enum ProximityTriggerVisualState : byte
+    {
+        State,
+    }
+
+    [Serializable, NetSerializable]
+    public enum TriggerVisuals : byte
     {
         VisualState,
     }
 
-    [NetSerializable]
-    [Serializable]
-    public enum TriggerVisualState
+    [Serializable, NetSerializable]
+    public enum TriggerVisualState : byte
     {
         Primed,
         Unprimed,