Prevent unit tests from sending emails

Updated unit tests accordingly. iBGP update is allowed only on routers with a provisioning or active trunk, not initial or terminated

create_router workflow takes a router to the PROVISIONING state
subscription service includes method for fetching all PROVISIONING routers
create_iptrunk workflow can now also select PROVISIONING routers next to ACTIVE ones

reformat some code
add PyYAML type hints
update the use of the LibreNMS client in the iBGP mesh workflow
update the conftest sample configuration fixture

add two subscription services that return all active IP trunks, and all trunks that terminate on a given router subscription

Added celery beat
Added workflow, task validation schedulling