Implement machine linking (#1784)

* Implement machine linking

* Cleanup and rename Signals

* Implement signal button

* Add machine linking signal mapping

* Fix signallink command help

* Add localization to signal linking and allow infinite range

* Add feedback for when a transmitter is not connected to any receivers

Refactor PopupMessage to use the entity extension
Refactor dependencies to not have to disable warnings

Content.Server/GameObjects/Components/MachineLinking/SignalSwitchComponent.cs

@@ -0,0 +1,87 @@
+using Content.Shared.GameObjects.EntitySystems;
+using Content.Shared.GameObjects.Verbs;
+using Content.Shared.Interfaces.GameObjects.Components;
+using Robust.Server.GameObjects;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Localization;
+using Robust.Shared.Serialization;
+
+namespace Content.Server.GameObjects.Components.MachineLinking
+{
+    [RegisterComponent]
+    public class SignalSwitchComponent : Component, IInteractHand, IActivate
+    {
+        public override string Name => "SignalSwitch";
+
+        private bool _on;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            UpdateSprite();
+        }
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+
+            serializer.DataField(ref _on, "on", true);
+        }
+
+        public void Activate(ActivateEventArgs eventArgs)
+        {
+            TransmitSignal(eventArgs.User);
+        }
+
+        public bool InteractHand(InteractHandEventArgs eventArgs)
+        {
+            TransmitSignal(eventArgs.User);
+            return true;
+        }
+
+        public void TransmitSignal(IEntity user)
+        {
+            _on = !_on;
+
+            UpdateSprite();
+
+            if (!Owner.TryGetComponent<SignalTransmitterComponent>(out var transmitter))
+            {
+                return;
+            }
+
+            transmitter.TransmitSignal(user, _on ? SignalState.On : SignalState.Off);
+        }
+
+        private void UpdateSprite()
+        {
+            if (Owner.TryGetComponent<SpriteComponent>(out var sprite))
+            {
+                sprite.LayerSetState(0, _on ? "on" : "off");
+            }
+        }
+
+        [Verb]
+        private sealed class ToggleSwitchVerb : Verb<SignalSwitchComponent>
+        {
+            protected override void Activate(IEntity user, SignalSwitchComponent component)
+            {
+                component.TransmitSignal(user);
+            }
+
+            protected override void GetData(IEntity user, SignalSwitchComponent component, VerbData data)
+            {
+                if (!ActionBlockerSystem.CanInteract(user))
+                {
+                    data.Visibility = VerbVisibility.Invisible;
+                    return;
+                }
+
+                data.Text = Loc.GetString("Toggle Switch");
+                data.Visibility = VerbVisibility.Visible;
+            }
+        }
+    }
+}