- Several feeds tested with QBoobMsg and apparently working correctly.
- NewsfeedBackend.set_message_read() untested, but should be working.
- weboob.tools.newsfeed provides content even when not provided as such by the
feed, using the "summary" instead.
using ICapMessages capability.
iter_threads and get_thread tested with weboob-cli and seem basically functional.
iter_unread_messages not working; set_message_read untested.