Issue #2512132 by Wim Leers, effulgentsia, Fabianx: Make CSRF links cacheable

core/core.services.yml

core/lib/Drupal.php

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

core/lib/Drupal/Core/Cache/Context/SessionCacheContext.php

core/lib/Drupal/Core/GeneratedLink.php

core/lib/Drupal/Core/GeneratedUrl.php

core/lib/Drupal/Core/Link.php

...pal/Core/PathProcessor/OutboundPathProcessorInterface.php

core/lib/Drupal/Core/PathProcessor/PathProcessorAlias.php

core/lib/Drupal/Core/PathProcessor/PathProcessorFront.php

core/lib/Drupal/Core/PathProcessor/PathProcessorManager.php

core/lib/Drupal/Core/Render/BubbleableMetadata.php

core/lib/Drupal/Core/Render/Element/Link.php

...l/Core/RouteProcessor/OutboundRouteProcessorInterface.php

.../lib/Drupal/Core/RouteProcessor/RouteProcessorCurrent.php

.../lib/Drupal/Core/RouteProcessor/RouteProcessorManager.php

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

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

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

core/lib/Drupal/Core/Template/TwigExtension.php