Migrate from dex to ZITADEL

[majst01]

Description

Actually dex is used with user: admin@metal-stack.io password: change-me
can be used with https://github.com/metal-stack/cli

metalctlv2 login will prompt you for this user.

It would be nice to have logto installed with a helm chart which creates the initial admin user and spits out the password or stores it in a secret. Also having a styled login page would be a nice bonus.

Useful Links:

• https://github.com/logto-io/logto
• https://github.com/appthrust/logto-helm
• https://github.com/appthrust/logto-admin-creator

[simcod]

After first investigation, we decided to use ZITADEL as OIDC solution instead of logto. Related implementation can be found in: #273