Manage collections / minimal solution viewer

### Collection overview

We think about a new concept for managing collections, especially in the viewer, but for now we found a minimal solution, where we don't need a lot of adjustments:

current version:

new version:

- we completely remove the right metadata side, then we can use the whole width for the viewer
- we integrate the description into the left sidebar
- I think we don't need the folder tab, here we only have the objects of the collection anyway
- we can already use a smaller size of the cards for the sidebar
- Annotation access is only displayed by the color of the annotation button: either it is blue and clickable if the user has access or it is greyed out and disabled if the user has no annotation access