Archive: start on UI for archive

Land some buttons. Clicking still has no effect.
note-obc.c: trailing space
Deleted signal: rename to trashed
manager, trash: allows to retrieve an archived note

get_item_at_path should return trashed note
local note, trash: delete the file when a note is definitely deleted

Just delete the file (signal and UI is still to be implemented)
trash : plug a deleted signal when an item is definitely deleted

The view removes the item.