Issue #2495833 by alexpott, tim.plunkett, dawehner: Drupal\node\NodePermissions::contentPermissions() is duplicate and dead code

Issue #2328411 by dawehner, geerlingguy, herom: Convert all permissions to yml files and permission callbacks.

Issue #2329485 by damiankloip, dawehner: Allow permissions.yml files to declare 'permission_callbacks' for dynamic permissions.