UX design for sharing

I am creating this issue to document the various ideas discussed so far for improving the UX of sharing app (include samba, web sharing and miniDLNA). Hopefully, this will facilitate further tweaks.

Related issues: #1796 (closed) , #1758 (closed). Related user request: https://discuss.freedombox.org/t/how-to-share-an-existing-mount-point-with-samba-app/948

Older design

Sharing2 work in !1808 (closed).