Issue #2177041 by dawehner, Berdir, jibran: Remove all implementations of hook_menu.

core/core.services.yml

core/includes/menu.inc

core/lib/Drupal/Core/EventSubscriber/PathRootsSubscriber.php

core/lib/Drupal/Core/Path/AliasWhitelist.php

core/modules/action/action.module

core/modules/aggregator/aggregator.module

core/modules/ban/ban.module

core/modules/block/block.module

core/modules/block/custom_block/custom_block.module

...ock/Plugin/Menu/LocalAction/CustomBlockAddLocalAction.php

.../tests/modules/custom_block_test/custom_block_test.module

core/modules/book/book.module

core/modules/comment/comment.module

core/modules/config/config.module

core/modules/config/tests/config_test/config_test.module

core/modules/config_translation/config_translation.module

core/modules/contact/contact.module

core/modules/content_translation/content_translation.module

core/modules/dblog/dblog.module

core/modules/editor/editor.module