Server errors can cause desync of cached data

[jordan-powers]

When the server reports an error, we open the error screen and display the error to the user. However, we should also either invalidate all cached data, or just force a reload of the page, since the error may have created a desync and invalidated the cache.

For example, if an attempt to check a student in fails on the server side, the client could still assume it succeeded and erroneously update the student's last_check_in. If the server reports an error, we should either invalidate the cache or just reload the whole page.