Minor paper ECS and stamps (#7394)

Co-authored-by: fishfish458 <fishfish458>

Content.Client/Paper/UI/PaperBoundUserInterface.cs

@@ -39,7 +39,7 @@ namespace Content.Client.Paper.UI
         {
             if (!string.IsNullOrEmpty(obj.Text))
             {
-                SendMessage(new PaperInputText(obj.Text));
+                SendMessage(new PaperInputTextMessage(obj.Text));
 
                 if (_window != null)
                 {

Content.Client/Paper/UI/PaperSystem.cs

@@ -0,0 +1,29 @@
+using Robust.Client.GameObjects;
+
+using static Content.Shared.Paper.SharedPaperComponent;
+
+namespace Content.Client.Paper;
+
+public sealed class PaperSystem : VisualizerSystem<PaperVisualsComponent>
+{
+    protected override void OnAppearanceChange(EntityUid uid, PaperVisualsComponent component, ref AppearanceChangeEvent args)
+    {
+        if (!TryComp(uid, out SpriteComponent? sprite))
+            return;
+
+        if (args.Component.TryGetData(PaperVisuals.Status , out PaperStatus writingStatus))
+            sprite.LayerSetVisible(PaperVisualLayers.Writing, writingStatus == PaperStatus.Written);
+
+        if (args.Component.TryGetData(PaperVisuals.Stamp, out string stampState))
+        {
+            sprite.LayerSetState(PaperVisualLayers.Stamp, stampState);
+            sprite.LayerSetVisible(PaperVisualLayers.Stamp, true);
+        }
+    }
+}
+
+public enum PaperVisualLayers
+{
+    Stamp,
+    Writing
+}

Content.Client/Paper/UI/PaperVisualsComponent.cs

@@ -0,0 +1,6 @@
+namespace Content.Client.Paper;
+
+[RegisterComponent]
+public sealed class PaperVisualsComponent : Component
+{
+}