Fix color picker dialog not staying inside the current screen.

Source/Editor/GUI/Dialogs/Dialog.cs

@@ -39,6 +39,11 @@ namespace FlaxEditor.GUI.Dialogs
         /// </summary>
         public DialogResult Result => _result;
 
+        /// <summary>
+        /// Returns the size of the dialog.
+        /// </summary>
+        public Float2 DialogSize => _dialogSize;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="Dialog"/> class.
         /// </summary>