[Entity] Brig Timers (#15285)

* brigtimer

* ok

* TextScreen w timer implementation

* second commit

* working brig timer

* signal timers near completion

* soon done

* removed licenses, fixes noRotation on screens, minor edits

* no message

* no message

* removed my last todos

* removed csproj.rej??

* missed a thing with .yml and tests

* fix tests

* Update base_structureairlocks.yml

* timespan type serialize

* activation turned into comp

* sloth review

* Update timer.yml

* small changes

---------

Co-authored-by: CommieFlowers <rasmus.cedergren@hotmail.com>
Co-authored-by: rolfero <45628623+rolfero@users.noreply.github.com>

Content.Shared/MachineLinking/SharedSignalTimerComponent.cs

@@ -0,0 +1,68 @@
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.MachineLinking;
+
+[Serializable, NetSerializable]
+public enum SignalTimerUiKey : byte
+{
+    Key
+}
+
+/// <summary>
+/// Represents a SignalTimerComponent state that can be sent to the client
+/// </summary>
+[Serializable, NetSerializable]
+public sealed class SignalTimerBoundUserInterfaceState : BoundUserInterfaceState
+{
+    public string CurrentText;
+    public string CurrentDelayMinutes;
+    public string CurrentDelaySeconds;
+    public bool ShowText;
+    public TimeSpan TriggerTime;
+    public bool TimerStarted;
+    public bool HasAccess;
+
+    public SignalTimerBoundUserInterfaceState(string currentText,
+        string currentDelayMinutes,
+        string currentDelaySeconds,
+        bool showText,
+        TimeSpan triggerTime,
+        bool timerStarted,
+        bool hasAccess)
+    {
+        CurrentText = currentText;
+        CurrentDelayMinutes = currentDelayMinutes;
+        CurrentDelaySeconds = currentDelaySeconds;
+        ShowText = showText;
+        TriggerTime = triggerTime;
+        TimerStarted = timerStarted;
+        HasAccess = hasAccess;
+    }
+}
+
+[Serializable, NetSerializable]
+public sealed class SignalTimerTextChangedMessage : BoundUserInterfaceMessage
+{
+    public string Text { get; }
+
+    public SignalTimerTextChangedMessage(string text)
+    {
+        Text = text;
+    }
+}
+
+[Serializable, NetSerializable]
+public sealed class SignalTimerDelayChangedMessage : BoundUserInterfaceMessage
+{
+    public TimeSpan Delay { get; }
+    public SignalTimerDelayChangedMessage(TimeSpan delay)
+    {
+        Delay = delay;
+    }
+}
+
+[Serializable, NetSerializable]
+public sealed class SignalTimerStartMessage : BoundUserInterfaceMessage
+{
+
+}