[1LP][RFR] Improve email tests.

[jarovo]

Purpose or Intent

For checking CC and Bcc we need improvement of mock SMTP server we have.

• Fixing smtp_test fixture should consider mails sent to cc and bcc  #8820
• Adding coverage for BZ-1783511

Tests ran on with my jenkins job due to problems with connection to the PRT container:
https://cfmeqe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/downstream-511-tests-jhenner/19/

In above, the virtualcenter provision_approval tests had problems to pass. They seem to be flaky as seen here:
https://cfmeqe-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/downstream-511-tests-jhenner/19/testReport/cfme.tests.cloud_infra_common/test_provisioning/
The failure seem not related:

>       wait_for(lambda: self.server_roles == roles, num_sec=timeout, delay=15)
E       wait_for.TimedOutError: Could not do 'lambda defined as `wait_for(lambda: self.server_roles == roles, num_sec=timeout, delay=15)`' at /var/ci/workspace/downstream-511-tests-jhenner/integration_tests/cfme/utils/appliance/__init__.py:1935 in time

Locally passed: cfme/tests/cloud_infra_common/test_provisioning.py::test_provision_approval[virtualcenter-6.7-edit] PASSED

{{py.test: -sv cfme/tests/cloud_infra_common/test_provisioning.py::test_provision_approval cfme/tests/configure/test_email.py::test_send_test_email --use-provider complete }}

[dajoRH]

I detected some fixture changes in commit 5278d32

The local fixture email_addresses_configuration is used in the following files:

• cfme/tests/cloud_infra_common/test_provisioning.py

Please, consider creating a PRT run to make sure your fixture changes do not break existing usage 😃