Improvements to hand labeler UI (#31833)

Give line edit focus when window is opened
No longer require pressing enter to set the text
Give feedback when user hits the maximum label length

Co-authored-by: Eoin Mcloughlin <helloworld@eoinrul.es>

Content.Client/Labels/UI/HandLabelerBoundUserInterface.cs

@@ -26,6 +26,11 @@ namespace Content.Client.Labels.UI
 
             _window = this.CreateWindow<HandLabelerWindow>();
 
+            if (_entManager.TryGetComponent(Owner, out HandLabelerComponent? labeler))
+            {
+                _window.SetMaxLabelLength(labeler!.MaxLabelChars);
+            }
+
             _window.OnLabelChanged += OnLabelChanged;
             Reload();
         }