Issue #2684577 by mohit_aghera, tim-diels, pooja saraah, gapple, smustgrave, quietone: Entity operations for menu links are hardcoded in edit menu form

Issue #2665992 by alexpott, klausi, heykarthikwithu, xjm, tstoeckler: @file is not required for classes, interfaces and traits

Issue #2479767 by Wim Leers: Fix MenuLinkInterface::isCacheable(): remove it in favor of implementing CacheableDependencyInterface

Issue #2347465 by tim.plunkett, dawehner, cilefen: Convert all instances of #type link/links to convert to use routes.

Issue #2277103 by tim.plunkett, pwolanin, Wim Leers, dawehner, hotpizzas: Switch Drupal::l() and LinkGenerator to expect a Url object.

Issue #2250315 by dawehner, pwolanin: Fixed Regression: Bring back node access optimization to menu trees.

Issue #2305707 by cilefen, pwolanin, dawehner, LinL: MenuLinkContent disabled field should be renamed to enabled and use positive logic.

Issue #2301273 by pwolanin, dawehner, Wim Leers, effulgentsia, joelpittet, larowlan, YesCT, kgoel: MenuLinkNG part2 (no UI or conversions): MenuLinkTree API and unit tests.

Issue #2301239 by pwolanin, dawehner, Wim Leers, effulgentsia, joelpittet, larowlan, xjm, YesCT, kgoel, victoru, berdir, likin, and plach: MenuLinkNG part1 (no UI or conversions): plugins (static + MenuLinkContent) + MenuLinkManager + MenuTreeStorage.