Updated simulator and aggregator to be consistent with the discussion on FQDNs and service function instances

See 

https://gitlab.it-innovation.soton.ac.uk/FLAME/flame-clmc/blob/mediaComponentConfig/docs/monitoring.md#user-content-configuration-status-modelling-and-monitoring

for documentation

Seeds random number generation for predictable results

conftest now simply returns an initialised simulator object

get_db_client -> influx_db

Also fixes field validation for unspecified metric data

Refactors simulator based fixtures in conftest and embeds MC config state into simulation boot sequence

Also removes superfluous file state & API state tests