[recovery] Improve recovery process user experience

[doobry-systemli]

To make the recovery process more comprehensible, a progress bar could be added:

• 25% after the process was started
• 50% after one came back and authenticated after the waiting period
• 75% after a new password was set
• 100% after the new recovery token was acknowledged

Also:

• explain in first step that people need their recovery token for the second step: "you have to come back to that very page and authenticate again with your mail and token"
• in second step, describe password policy (same box as during registration)
• in second step, explain: you have to login and create a new recovery token
• after second step, auto login and display new generated recovery token