* [core] Add tx-pool txn interface & update supporting components
* Add txn interface (`PoolTransaction`) for tx-pool
* Update tx_journal to handle pool's txn interface
* Update tx_list to handle pool's txn interface
* [staking] Satisfy `PoolTransaction` interface & move error sink types
* Implement `Protected`, `ToShardID`, `To`, `Data`, `Value` and `Size`
for `StakingTransaction` to satisfy `PoolTransaction` interface
* Refactor `Price` to `GasPrice` for `StakingTransaction` to
satisfy `PoolTransaction` interface
* Move error sink related components to transaction.go
* Expose `VerifyBLSKey` and `VerifyBLSKeys`
* [core] Generalize tx pool & refactor error sink logic
* Refactor txn logic to use `PoolTransaction` and `PoolTransactions`
* Add `txPoolErrorReporter` to handle reporting to plainTx and stakingTx
error sinks
* Remove old & unpayable txs error reports (to error sink) since errs
are already reported when adding the txs
* Fix known transaction error report when adding txn batches
* Add error sink reporting when failed to enqueue txs
* [node] Fix error sink & update tx pool interaction
* Integrate staking transaction in tx-pool
* Remove staking transaction error sink
* [hmy api] Integrate staking transactions from tx pool
* Remove looking at tx pool for `GetTransactionByHash`
* Add `PendingStakingTransactions` and update `PendingTransactions` to
only return plainTx
* [tests] Update all tests for tx pool txn interface & staking err sink
* Update transactions to `PoolTransaction` interface
* Remove `CommitTransactions` staking txn error sink
* Add basic staking txn tests to tx pool tests
* [node] Make all node broadcast staking tx and plain tx
* [core + staking] Separate staking msg check and put in tx pool
* Move `Validator` specific sanity check into its own method and
call said method in `ValidatorWrapper` sanity check
* Create staking msg verifiers and preprocessors in `staking_verifier.go`
* Remove staking msg verification on all staking msg applications
in `state_transition.go` and call new staking msg verifiers & preprocessors
* Add staking msg verification to tx pool
* Remove `ToShardID` from `PoolTransaction` interface and remove trivial
implementation of `ToShardID` in `StakingTransaction`
To verify the signature of downloaded binaries, make it optional.
For engineering build, there is no need to verify the signature.
Signed-off-by: Leo Chen <leo@harmony.one>
* update testnet epochs
* Fix the one-off error fully
* Add const for the bad block num
* Graceful shutdown of node
* Add syscall.SIGTERM for shutdown
* Add transaction base fee for createValidator as 10x of create contract
* Add transaction base fee for createValidator as 100x of create contract
* Add transaction base fee for createValidator as 10x of create contract
* Add transaction base fee for createValidator as 100x of create contract
* Fix lint
* [consensus] Remove unnecessary usage of bandwidth in network messages, small adjustments after consensus code review
* [consensus] Factor out behavior of when quorum prepare reached
* [consensus] Push code from another scratch branch
* [consensus] Still do need to accept higher than blocknum message