Before this PR, the "can reconnect after late close event" test
was relying on the `nextTick` helper to check which bus events
were received when the device switches from online to offline.
This test was non deterministic since a tick might not be enough
to receive the related events: the bus service communicates with
a shared worker through the MessagePort API, the worker uses a
Websocket which dispatch events upon connection/reconnection.
This commit replaces the use of the `nextTick` helper by the
dedicated `waitForBusEvent` helper which resolves once the event
is received.
fixed runbot-45695
closesodoo/odoo#147068
Signed-off-by: Matthieu Stockbauer (tsm) <tsm@odoo.com>