Save (unauthenticated) time slot selection on log in

[SamuAlfageme]

Hey newdlers! 🍜 I was just hit by this and thought it might be a nice UX enhancement for the project:

Steps to reproduce:

1. Open a newdle on incognito mode.
2. Fill in your availability.
3. Realize you're not authenticated and hit the "Log in" button.
4. Login through your IDP.

Expected result

The newdle no longer asks me Who are you? and allows me to send my answer already.

Actual result

I'm logged in, but my availability selection has been cleared.