Handle timeout on wayf

[phavekes]

This issue is imported from pivotal - Originaly created at Feb 26, 2019 by Thijs Kinkhorst

Go to a service and press the login button. Be redirected to SURFconext's wayf. Do not do anything. Wait for time t where t > EB session length. Then click something. Hard error.

Catch this in some way and tell the user that they waited to long and they should retry from the SP.

(It's likely not useful to try to 'repair' this and have the login still work, as the SP has sent the authnrequest say 1 h ago, we cannot expect the SP do to something useful with the assertion.)

[phavekes]

Is this fixed with #164076545? In the described situation, we would now show the session lost error message. 

If we want a WAYF specific session lost message, we must look into the possibilities to identify the location where the timeout occurred.

We could also kit out the consent screen with a similar construction while we are at it?

@thijskh @pmeulen @bartgeesink . Can you join the discussion (Michiel Kodde - May 2, 2019)