Port request: Render cache

[jenlampton]

Name of the module, theme, or layout render_cache

Link to the drupal.org module, theme, or layout https://www.drupal.org/project/render_cache

Link to D7 source code https://git.drupalcode.org/project/render_cache

(Optional) Link to an issue in the drupal.org queue asking the Drupal community if anyone is working on a Backdrop port of this project todo