Feedback Button Block: No Feedback Response when a site is private

When a site is private, feedback sent through Feedback Button Block doesn't appear in Coursignal Dashboard: https://app.crowdsignal.com/dashboard.

Not sure if this is a bug or intended. But in some cases, users may want to use this feature even on private sites.

Start by reproducing the Feedback Button Block behavior on a private site and compare it with the Crowdsignal Dashboard at https://app.crowdsignal.com/dashboard. Determine whether missing responses are intended for private sites; done means the behavior is clarified and, if it is a bug, private-site feedback appears in the dashboard.

Written by the indexing model from the issue text.