Adds Neutron update Network and subnets benchmarks:

- NeutronNetwork.create_and_update_networks

- NeutronNetwork.create_and_update_subnets

Partial implementation of blueprint benchmark-scenarios-for-neutron-update

Change-Id: I88f1f1f30c141fa88a0b336645e35c6023aca461
Merge "Adds Neutron update Network and subnets benchmarks:"