[DERCBOT-1859] Allow label for namespaces

[scezen]

Ticket : DERCBOT-1859

Goal

Add a label for namespaces, with a fallback to the technical namespace when no label is defined.

Details

• Added an optional label field in NamespaceConfiguration
• NamespaceConfiguration (was used for Sharing Settings option and created in Mongo only when one option was activated in namespace settings) is now created automatically when a namespace is created
• The backend now returns a resolved label for namespaces:
  • Custom label if defined
  • Otherwise the technical namespace
• Updated the main namespace displays in the Studio to show the label when present

Note

• No breaking change: if no label is set, the UI still works with the technical namespace

Also included in this PR:

• Display of footnote details in the Dialogs view

[assouktim]

Thanks! Looks good to me.
One thing to improve though: updating a label requires a browser refresh for the change to be visible at the namespace list and in the header.

[rkuffer]

Ok for me for the front part of this PR

[assouktim]

Thanks!