[Feature Request] Multi-user quick switch

Description Intention / Why? For people that share a computer (pretty common in a household) or people who want to digitalize both personal and other documents (for example for voluntary work in sports), it's really useful to have 2 different paperless-ngx accounts, so the documents etc. don't mix. But having to fully log off and log in again when you want to switch your users, is kinda cumbersome. Feature Request Instead it would be nice to have the ability to quickly switch between multiple users, without having to explicitly log out and log in again. Github has a pretty good version of that: <img width="342" height="134" alt="grafik" src=" /> If you would log in with a second account, you would see a list of these and can switch between them with a single click. (I only have 1 account, so the list is empty) Implementation Suggestions In the user menu in the top right corner a new button would be added like this <i…