Issue #3261957 by longwave, quietone, andypost: Properly deprecate migrate_drupal_multilingual for future removal

Issue #3133162 by jungle, ravi.shankar, Deepak Goyal, Neslee Canil Pinto, anmolgoyal74, xjm, Kristen Pol: Replace the start verb Test with Tests in method comments of tests

Issue #2822382 by voleger, pfrenssen, erozqba, jungle, RytoEX, borisson_, jofitz, shashikant_chauhan, sidharthap, dawehner, xjm, kiamlaluno, catch, daffie, klausi: Make every $modules property protected on classes extending BrowserTestBase and KernelTestBase

Issue #3107732 by mondrake, longwave, swatichouhan012, salah1, xjm, catch, alexpott, Berdir: Between April 13 and April 17, 2020: Add return typehints to setUp/tearDown methods in concrete test classes

Revert "Issue #2822382 by voleger, pfrenssen, erozqba, RytoEX, borisson_, sidharthap, Jo Fitzgerald, shashikant_chauhan: Make every  property protected on classes extending BrowserTestBase and KernelTestBase"

This reverts commit 69501f30.

Issue #2822382 by voleger, pfrenssen, erozqba, RytoEX, borisson_, sidharthap, Jo Fitzgerald, shashikant_chauhan: Make every  property protected on classes extending BrowserTestBase and KernelTestBase

Issue #2953360 by quietone, heddn, yogeshmpawar, phenaproxima, Gábor Hojtsy, maxocub, catch, alexpott, masipila: Experimental migrate_drupal_multilingual module

Issue #2912348 by maxocub, Jo Fitzgerald, masipila, heddn, phenaproxima: Handle entity_references related to Drupal 6 and 7 node translations with different IDs