OIDC device flow: visual indication that notebook is waiting

[soxofaan]

When doing the OIDC device flow in a notebook (or even as a regular script), the con.authenticate_oidc() call (or related) will print something like

To authenticate: visit https://aai.egi.eu/oidc/device and enter the user code 'F0oB6r'.

and then do noting (except waiting).

It would be cool if there was a more visual indication that the client code is waiting for the user to do something: e.g. some kind of spinner, progress bar (based on waiting timeout), ...

[soxofaan]

problem with current implementation: output text widget in jupyter notebook is now refreshed every 1, which makes it hard/impossible to select the url or code for copy pasting, which is a usability regression

[soxofaan]

Also to do: progress bar should be cleaned up (or a new line should be added), now it looks like this:

To authenticate: visit https://aai.egi.eu/oidc/device and enter the user code '.....'.
Authorized successfully.   ] Waiting for authentication.             
Authenticated using device code flow.

[soxofaan]

implemented in #420