Public link via token no longer works

[Steve-MP]

The facility to access a panel using a public token has been lost in the process of moving the single panel view into the Vue JS application. The token is no longer passed in the request to the back end, so only user account authorisation is attempted on the back end, which will always fail when no user is logged in.

Replication: Generate a token using the "Get Link and QR Code" button, log out, try using the link.