Update node account status to Standby status once operator provide a full set trust account key set

as soon as the whitelisted node use sscli tool to set their trust account

{
      "bnb_signer_acc": "tbnb190tgp5uchnlcpsk7n7nffypkwlzhcqge27xkfh",
      "bep_observer_acc": "bep1djtsmryw3zxsczuecpf507nssxjamuqse4q064",
      "bepv_validator_acc": "bepcpub1zcjduepqalrjfr35yz8m779kdhmzr5su63p9vlz6r5xzpyyqveaa0crze62q4xpe9q"
}

then we mark their node account as standby

once they send a transaction using the address specified in bnb_signer_acc(tbnb190tgp5uchnlcpsk7n7nffypkwlzhcqge27xkfh) to existing pool address with memo NEXTPOOL then we mark their node account as ready, we will use the sender to identify which node account it is