Issue #3417566 by quietone, smustgrave, longwave: Correct more words in comments plus pathnames

core/INSTALL.mysql.txt

core/INSTALL.pgsql.txt

core/assets/scaffold/files/default.settings.php

core/assets/scaffold/files/example.sites.php

core/lib/Drupal.php

core/lib/Drupal/Component/Utility/HtmlSerializerRules.php

core/lib/Drupal/Core/Access/CsrfTokenGenerator.php

core/lib/Drupal/Core/Database/Install/Tasks.php

...upal/Core/Database/Transaction/TransactionManagerBase.php

core/lib/Drupal/Core/DrupalKernel.php

core/lib/Drupal/Core/Entity/EntityForm.php

core/lib/Drupal/Core/Extension/DatabaseDriverList.php

core/lib/Drupal/Core/Extension/ExtensionList.php

core/lib/Drupal/Core/Installer/ExtensionListTrait.php

...b/Drupal/Core/Render/HtmlResponseAttachmentsProcessor.php

core/lib/Drupal/Core/Routing/RouteProvider.php

core/lib/Drupal/Core/Test/TestDiscovery.php

core/lib/Drupal/Core/Update/UpdateRegistry.php

core/misc/ajax.js

core/misc/cspell/dictionary.txt