* Add Vote Contract
* Move ownership of LeaderScheduler from Fullnode to the bank
* Modified ReplicateStage to consume leader information from bank
* Restart RPC Services in Leader To Validator Transition
* Make VoteContract Context Free
* Remove voting from ClusterInfo and Tpu
* Remove dependency on ActiveValidators in LeaderScheduler
* Switch VoteContract to have two steps 1) Register 2) Vote. Change thin client to create + register a voting account on fullnode startup
* Remove check in leader_to_validator transition for unique references to bank, b/c jsonrpc service and rpcpubsub hold references through jsonhttpserver
* Move ledger write to its own stage
- Also, rename write_stage to leader_vote_stage, as write functionality
is moved to a different stage
* Address review comments
* Fix leader rotation test failure
* address review comments
* Add PoH height to process_ledger()
* Moved broadcast_stage Leader Scheduling logic to use Poh height instead of entry_height
* Moved LeaderScheduler logic to PoH in ReplicateStage
* Fix Leader scheduling tests to use PoH instead of entry height
* Change is_leader detection in repair() to use PoH instead of entry height
* Add tests to LeaderScheduler for new functionality
* fix Entry::new and genesis block PoH counts
* Moved LeaderScheduler to PoH ticks
* Cleanup to resolve PR comments
* Added LeaderScheduler module and tests
* plumbing for LeaderScheduler in Fullnode + tests. Add vote processing for active set to ReplicateStage and WriteStage
* Add LeaderScheduler plumbing for Tvu, window, and tests
* Fix bank and switch tests to use new LeaderScheduler
* move leader rotation check from window service to replicate stage
* Add replicate_stage leader rotation exit test
* removed leader scheduler from the window service and associated modules/tests
* Corrected is_leader calculation in repair() function in window.rs
* Integrate LeaderScheduler with write_stage for leader to validator transitions
* Integrated LeaderScheduler with BroadcastStage
* Removed gossip leader rotation from crdt
* Add multi validator, leader test
* Comments and cleanup
* Remove unneeded checks from broadcast stage
* Fix case where a validator/leader need to immediately transition on startup after reading ledger and seeing they are not in the correct role
* Set new leader in validator -> validator transitions
* Clean up for PR comments, refactor LeaderScheduler from process_entry/process_ledger_tail
* Cleaned out LeaderScheduler options, implemented LeaderScheduler strategy that only picks the bootstrap leader to support existing tests, drone/airdrops
* Ignore test_full_leader_validator_network test due to bug where the next leader in line fails to get the last entry before rotation (b/c it hasn't started up yet). Added a test test_dropped_handoff_recovery go track this bug