Сообщения в ПДА (#564)

* add: Сообщения в ПДА

* Search bar and colors in messages on the PDA

Content.Shared/_White/CartridgeLoader/Cartridges/MessagesUiMessageEvent.cs

@@ -0,0 +1,26 @@
+using Content.Shared.CartridgeLoader;
+using Robust.Shared.Serialization;
+
+namespace Content.Shared._White.CartridgeLoader.Cartridges;
+
+[Serializable, NetSerializable]
+public sealed class MessagesUiMessageEvent : CartridgeMessageEvent
+{
+    public readonly MessagesUiAction Action;
+    public readonly int? TargetChatUid;
+    public readonly string? StringInput;
+
+    public MessagesUiMessageEvent(MessagesUiAction action, string? stringInput, int? targetChatUid)
+    {
+        Action = action;
+        TargetChatUid = targetChatUid;
+        StringInput = stringInput;
+    }
+}
+
+[Serializable, NetSerializable]
+public enum MessagesUiAction : byte
+{
+    Send,
+    ChangeChat
+}