fix: Error 422 after session timeout

[Quentinchampenois]

🎩 Description

Please describe your pull request.

When user is logged in and session expires, she is automatically logged out. When user is logged out from a restrictive route, she is redirected to signin route without reload and CSRF token is now expired on form submit, causing a 422 Error "InvalidAuthenticityToken"

This PRs aims to change after_sign_out_path from "request.referer" to "stored_location_for(user)"

📌 Related Issues

Link your PR to an issue

• Notion card

Testing

Describe the best way to test or validate your PR.

• Run application with env var DECIDIM_SESSION_TIMEOUT=1 (unit: Minutes)
• Log in as user
• Access restrictive route like /admin
• Wait a minute to be automatically logged out
• Log again
• You should not see a blank screen

Testing using Docker

• Replace DECIDIM_SESSION_TIMEOUT value in both services in file docker-compose.local.yml
• Run make run
• Wait containers to be ready
• Access https://localhost:3000

Tasks

• Add specs
• Extend Sign out path in sessions controller
• Add env var DECIDIM_SESSION_TIMEOUT

Extra info

• Add env var DECIDIM_SESSION_TIMEOUT
• I am not completely sure if it really solves the 422 issue on log out but I can't reproduce this behaviour with this fix.