When setting the listeners in the IMAP Folder, we avoid setting more
than one listener for the same imap mailbox (because in some situations
we were registering way too many listeners).

this was making the pixelated inbox registering the notification and
therefore the imap mailbox not being registered.

this MR also refactors the way pixelated is initialized, so that it
avoid creating a second Account instance. In this way, we make sure that
the pixelated mua and the imap server share the same collections for a
given mailbox, and therefore any of the two is able to get a
notification whenever the other adds a message to the mailbox.

- Resolves: #8846, #8798

Related with: https://github.com/pixelated/pixelated-user-agent/issues/924
with @aarni

Signed-off-by: Ruben Pollan <meskio@sindominio.net>

implements a global auth token for the app.

this token is written to .config/leap/authtoken, and passed to the
anchor part of the landing URI when opening the index resource by the
browser.

- Resolves: #8765

Active user is now only a concept of the cli. For it we add a
~/.config/leap/bitmaskctl.cfg file.

- Resolves: #8769

- Resolves: #8755

encode to ascii any parameter passed as unicode.

so that whitelisting doesn't have to peek into the data.
added more documentation and some tests stubs too.