[14.0][FIX] l10n_it_bill_of_entry: Multi company management in tests

[toita86]

The user must be logged in only one company for the tests to behave as expected. For instance, searching for a journal should only find journals in the current company

backport of https://github.com/OCA/l10n-italy/pull/4193

[francesco-ooops]

@SirAionTech buona per te?