Improved transactions data sent in network monitor

[alexisbatyk]

Tasks included on this issue:

• Add contracts_data to ServerState in network_metrics_server.rs in fdev.
• Task included: Send all transaction history when the ws connection starts.
• Task included: Store contract data on fn save_record when pushing a new event.

[iduartgomez]

@alexisbatyk can we close this issue?

[iduartgomez]

Done, re-opem if necessary @alexisbatyk