CloseNotification Test outdated

[amouhoub]

The CloseNotification (test/ui/commands/closeNotification.js) test consists in simulating closing notifications or waiting for them to close.
This test used to work perfectly until the introduction of new notifications (variables/GI duplicates alert) that requires being closed manually without any timeout.
Therefore, this test needs to be adapted to simulate closing these properly and not wait for them to close themselves because it will never happen !!!

@paraita @aminelouati