[IMP] test_main_flows: adapt The Main Flow Tour for mobile

This PR adapts some existing steps or add new ones to execute
the same tour on mobile.

This tour has many steps and give a good idea to know if new tasks
broke mobile or not.
The goal is that even if the design isn't perfect, users aren't blocked
and are able to perform their usual tasks.

The main flow tour is still running on desktop but
we also run it a second time on mobile.
It's only available in enterprise, otherwise the test will be skipped.
'375x667' correspond to the Bootstrap XS size.
This value is already used for the mobile tests suite.

Also see https://github.com/odoo/enterprise/pull/9011



Task ID: 2149402

closes odoo/odoo#46880

Related: odoo/enterprise#9011
Signed-off-by: Adrien Dieudonné (adr) <adr@odoo.com>