This commits adds to the existing conditional visibility option
introduced in [1], the option to display or hide blocs to a user,
depending on if he's logged in or not.
A select widget was added as an alternative to the many2one widgets that
were currently used, as we don't need to connect to the database to
display logged in/logged out option.
[1]: 1c442782f8
task-2618946
closes odoo/odoo#76609
X-original-commit: a42634f8cef57dce0a6a5a09408c3f5823fc647a
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>