- Use the 'session' class of the JS Framework (session no lounger bound
to web client)
- Test change: compare emitted & received messages based on content, not
order. Using string comparison raises false positives.
Fix a check when comparing a user count with items within a mock call.
The previous method was succeeding by pure luck because OCA test
databases contain 2 users, which happens to be the amount of items
within a mock "call_args" (it contains args + kwargs).
