[N4] dBFT with Double Speakers

[vncoelho]

We have designed, conducted extensive tests, published papers and mathematical models (MILP) for dBFT 1.0, dBFT 2.0 and double speakers.
The research can not be lost because double speakers is a great improvement that can improve stability and open opportunities for interesting scenarios for running CNs with fallback primaries (collaborative nodes can randomly participate and propose blocks every block without any issue).
It is as important as porting Anti-MEV addition to dBFT 2.0 from NeoX to N4.

For such reason, we will be porting the PR neo-project/neo#3254 to N4.

We hope we can soon merge the PR, it has beeb battle tested for years by our team
, and it should be the standard for our tests during N4 development.