Revert "Add FolderUID for library elements" (#83776)

Revert "Add FolderUID for library elements (#79572)"

This reverts commit 2532047e7a.

pkg/api/dashboard_test.go

@@ -1037,7 +1037,7 @@ func (m *mockLibraryPanelService) ConnectLibraryPanelsForDashboard(c context.Con
 	return nil
 }
 
-func (m *mockLibraryPanelService) ImportLibraryPanelsForDashboard(c context.Context, signedInUser identity.Requester, libraryPanels *simplejson.Json, panels []any, folderID int64, folderUID string) error {
+func (m *mockLibraryPanelService) ImportLibraryPanelsForDashboard(c context.Context, signedInUser identity.Requester, libraryPanels *simplejson.Json, panels []any, folderID int64) error {
 	return nil
 }