[FIX] bus: fix im_status during tests

Before this PR, the `_mockIrWebsocket__updatePresence` route of the
bus mock server could lead to errors when no im status ids were
provided. This commit fixes this issue by ensuring im status ids
were passed before calling `_mockIrWebsocket__getImStatus` method.

Moreover, old longpolling routes were still present on the bus mock
server. This commit removes these routes.

closes odoo/odoo#100583

closes odoo/odoo#100651

Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>