Revert "Issue #2560641 by alexpott, lauriii, Xano, borisson_, ianthomas_uk: Remove all usages SafeMarkup::checkPlain() from render arrays"

This reverts commit 31007609.

Issue #2560641 by alexpott, lauriii, Xano, borisson_, ianthomas_uk: Remove all usages SafeMarkup::checkPlain() from render arrays

Issue #1392754 by tss, justAChris, jhodgdon: Comply with new documentation standards for @file for namespaced class files

Issue #2357199 by andypost, naiduharish: Consider CommentManagerInterface::addDefaultField() as deprecated and remove in favour of CommentTestTrait

Issue #2306407 by lauriii, penyaskito, mortendk, pakmanlh, Wim Leers, ypogue: Remove breadcrumb from page template

Issue #2380773 by tibbsa, hussainweb, Mile23: Clean-up Node module test members - ensure property definition and use of camelCase naming convention

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #578400 by aaronschachter, melsi, Gábor Hojtsy, valthebald, idflood, sign, Damien Tournoud: Fixed Display the page title, even if 0.

Issue #2004252 by mortendk, babruix, dasjo, joelpittet, visabhishek, cwells, jenlampton, Dragan Eror, nikhiltri, minneapolisdan, Manuel Garcia, sarahjean, acouch | scor: Node.html.twig template.

Issue #1988612 by effulgentsia, yched, Wim Leers, Berdir, Pancho: Apply formatters and widgets to rendered entity base fields, starting with node.title.

Issue #731724 by larowlan, andypost, dixon_, tsvenson: Convert comment settings into a field to make them work with CMI and non-node entities.

Issue #1806334 by dawehner, xjm, tim.plunkett, rootatwc: Convert the node listing at /node to Views.

Issue #1711070 by kid_icarus, tim.plunkett, xjm, droplet, zendoodles and cam8001: Convert tests to use ::$modules property instead of parent::setUp($modules).