Autorotate effect slow performance

Problem/Motivation

The "autorotate" effect causes pages with a lot of images to load slowly.

#3213897: Autorotate effect does not update image dimensions → introduced a fix for incorrect width and height attributes on autorotated images by examining the image file itself during ::transformDimensions(). This ends up causing pages with lots of images to render slowly.

My workaround is currently to cache the autorotate value for each image in Drupal::state() so the image doesn't have to be parsed each time. But maybe there's a cleaner solution?