Don't raise exception when allocating existing host/network or deleting non-existent ones

Updated delete Netbox device functionality to delete the device if it exists and don't raise AttributeError.

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

the optional label remains, if found to be useful at a later point in time

added import script for reading partners from csv files

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