Keyframes - Copy/paste WIP

Timeline - Improved sizing, avoid unnecessary scrolling
Timeline - Fix selection rectangle appearing on mousedown

src/Artemis.UI.Shared/Services/Interfaces/IProfileEditorService.cs

@@ -156,6 +156,11 @@ namespace Artemis.UI.Shared.Services
         /// <returns>The pasted render element</returns>
         ProfileElement? PasteProfileElement(Folder target, int position);
 
+        /// <summary>
+        ///     Gets a boolean indicating whether a profile element is on the clipboard
+        /// </summary>
+        bool GetCanPasteProfileElement();
+        
         /// <summary>
         ///     Occurs when a new profile is selected
         /// </summary>

src/Artemis.UI.Shared/Services/ProfileEditorService.cs

@@ -384,6 +384,12 @@ namespace Artemis.UI.Shared.Services
             return clipboardObject != null ? PasteClipboardData(clipboardObject, target, position) : null;
         }
 
+        public bool GetCanPasteProfileElement()
+        {
+            object? clipboardObject = JsonClipboard.GetData();
+            return clipboardObject is LayerEntity || clipboardObject is FolderClipboardModel;
+        }
+
         private RenderProfileElement? PasteClipboardData(object clipboardObject, Folder target, int position)
         {
             RenderProfileElement? pasted = null;