*: im_livechat, test_mail, test_mail_full. The createMessagingMenu helper was used during tests to mount the messaging menu and test it. However, this approach is not very realistic and blocks some waiting PRs. In order to get closer from the reality, let's instanciate a webClient and a systrayService for the messagingMenu to be present at all time. closes odoo/odoo#94301 Related: odoo/enterprise#28747 Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>