Add TRANSACTION_STATUS_REJECTED_SYSTEM_ERROR

[talkol]

This is required when we're adding a new transaction, calling the preOrder check contract and the contract execution fails due to some reason.. this means that we're rejecting the transaction because of a system error

1. Add to spec

2. Add to all clients sdks + gamma-cli

3. Return it in services/transactionpool/add_new_transaction.go here:

if err := s.validateSingleTransactionForPreOrder(ctx, input.SignedTransaction); err != nil {
    status := protocol.TRANSACTION_STATUS_REJECTED_SMART_CONTRACT_PRE_ORDER // TODO: change to system error

[electricmonk]

@OdedWx this is a protocol change - please consider