Use Symfony Request for system module

Part of #1998638: [Meta] Refactor raw PHP variables (e.g $_SERVER, $_REQUEST, $_GET, $_POST) with Symfony Request object

Files that need converting are:

• core/modules/system/lib/Drupal/system/Tests/Bootstrap/OverrideServerVariablesUnitTest.php
• core/modules/system/lib/Drupal/system/Tests/Common/RenderTest.php
• core/modules/system/lib/Drupal/system/Tests/Common/TableSortExtenderUnitTest.php
• core/modules/system/lib/Drupal/system/Tests/Database/SelectPagerDefaultTest.php
• core/modules/system/lib/Drupal/system/Tests/Entity/EntityQueryTest.php
• core/modules/system/lib/Drupal/system/Tests/Form/TriggeringElementTest.php
• core/modules/system/lib/Drupal/system/Tests/Theme/RegistryTest.php
• core/modules/system/system.admin.inc
• core/modules/system/system.api.php
• core/modules/system/system.install
• core/modules/system/system.module
• core/modules/system/tests/http.php
• core/modules/system/tests/https.php
• core/modules/system/tests/modules/ajax_test/ajax_test.module
• core/modules/system/tests/modules/form_test/form_test.module
• core/modules/system/tests/modules/menu_test/menu_test.module:
• core/modules/system/tests/modules/system_test/system_test.module
• core/modules/system/tests/modules/session_test/session_test.module