Issue #2972308 by Berdir, mbovan, johnwebdev, jpatel657, benjifisher, plach, xjm, jigarius, geek-merlin: Allow users to translate content they can edit

Issue #2975666 by maxocub, benjifisher, masipila, jcnventura, jigarius, phenaproxima, catch, quietone: Migrate Drupal 7 node entity translations data to Drupal 8

Issue #2936463 by jigarius, ragasirtahk, Jo Fitzgerald, zuhair_ak, heddn, larowlan, quietone: Throw exception when "callable" plugin is called with undefined on invalid callback