Rebuild cache after cache is cleared

Problem/Motivation

After a cache rebuild, a page that renders a contributions block falls back to the waiting-for-credits message.

Steps to reproduce

• Add config for an organization.
• Add contrib blocks to a page.
• Clear cache and reload page.
• Note that the issue credits are not rendered - a message saying they are being fetched is shown instead.
• Run the drush command to fetch credits (drush contribution:fetch) and reload page.
• Note that the issue credits are now rendered.

Proposed resolution

Add a hook to rebuild cache upon cache clear.