[Publisher] Update loading error display logic to handle migration errors

[mxosman]

We recently had the following migration error, which resulted in the staging version of the app to display the No agency has been connected to this account. error message.

This one may be a bit tricky because the logic in updateAndRetrieveUserPermissionsAndAgencies sets the loadingError to true if an error was raised during the request/response, and since the loadingError was not set to true, it appears that the request went through and received a response successfully, but with no list of agencies (current assumption). We should explore a potential solution for this edge-case if one is possible on the FE.