[consensus] add ability to control safety rules service
[consensus] add ability to control safety rules service

At start we'll have the safety rules service that runs in the same
thread / process called local.
Soon we'll have one called remote that will be used for interprocess
communication.

Closes: #2065
Approved by: dmitri-perelman

libra/libra,aptos-labs/aptos-core,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,libra/libra,libra/libra,aptos-labs/aptos-core