Client-side login for DRES

[sauterl]

This issue should target the VBS23 branch.

Based on experience, it might be better to have a dedicated login for DRES as a form in the DRES sidebar instead of the currently, cookie based solution.

• Add a form with username / password information and a login button to the DRES sidebar config
• Make it toggleable in the config to use either the cookei based or new login-form to log-in to dres
• Use this new method to log-in to DRES to get the currently displayed information as well as when submitting