feat: logout system redesign (!95) · Merge requests · Perun / Perun ProxyIdP / ProxyIdP GUI

Description

Redesign of the logout page based on the proposed design in Figma adjusted to work with the MUNI framework. Changes:

the first page displays a configurable picture to illustrate the proxy logout meaning
progress bar is added
configurable proxy name is added to the config (display name for logout screens to specify name instead of showing just "proxy")
ssp session cookies are deleted after the first screen and are temporarily kept in the flask session instead
the service logout uses a checkbox to include all devices instead of a second button
the service logout shows only one list if service sessions == device sessions
the third screen shows only the loading status - the failed logouts are moved to the last page
the last page includes an overview of failed/unknown status logouts and successful logouts (if any category is empty, it is not included in the final screen)
"Back to XXX service" button is shown on the last page if a link is available, otherwise, it's hidden

deploy proxyIdP GUI to id-test from the feature branch
make sure you're logged in to some service using proxy, e.g. INET or GitLab (you might need to log out and then log back in to make sure the cookie is being passed to the logout page)
access the logout page

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