Issue #2004334 by pwolanin, dawehner, fubhy: Separate Tabs (MENU_LOCAL_TASK) from hook_menu().

core/core.services.yml

core/includes/menu.inc

core/lib/Drupal/Core/Annotation/Menu/LocalTask.php

core/lib/Drupal/Core/Menu/LocalTaskBase.php

core/lib/Drupal/Core/Menu/LocalTaskInterface.php

core/lib/Drupal/Core/Menu/LocalTaskManager.php

...es/system/lib/Drupal/system/Tests/Menu/LocalTasksTest.php

core/modules/system/system.api.php

.../Drupal/menu_test/Plugin/Menu/LocalTask/TestTasksEdit.php

...pal/menu_test/Plugin/Menu/LocalTask/TestTasksSettings.php

...menu_test/Plugin/Menu/LocalTask/TestTasksSettingsSub1.php

...menu_test/Plugin/Menu/LocalTask/TestTasksSettingsSub2.php

.../Drupal/menu_test/Plugin/Menu/LocalTask/TestTasksView.php

core/modules/system/tests/modules/menu_test/menu_test.module

...ules/system/tests/modules/menu_test/menu_test.routing.yml

...b/Drupal/views_ui/Plugin/Menu/LocalTask/ViewsListTask.php

...ws_ui/Plugin/Menu/LocalTask/ViewsSettingsAdvancedTask.php

...views_ui/Plugin/Menu/LocalTask/ViewsSettingsBasicTask.php

...upal/views_ui/Plugin/Menu/LocalTask/ViewsSettingsTask.php

core/modules/views_ui/views_ui.module