Part 1: 2301239, clean up MenuLinkBase related to comment #5.
Issue# 2256521 by kgoel: Created new issue if menu link value matches with original value in MenuTreeStorage.php
Issue# 2256521 by kgoel: fixed typo in MenuTreeStorage.php
fix @todo about loading by route name
Issue# 2256521 by kgoel: Created issue for adding has_any-children todo in MenuTreeStorage.php
START PART 2:  https://www.drupal.org/node/2301273
apply patch https://www.drupal.org/files/issues/menu-2256521-MenuLinkTree-review-do-not-test.patch
START PART 3: https://www.drupal.org/node/2301313
apply patch https://www.drupal.org/files/issues/menu-2256521-MenuLinkContentUI-review-do-not-test.patch