Add KMS functionality(Triage on ostracon#417)

[0Tech]

The subject of the triage:

• Add KMS functionality ostracon#417

[jaeseung-bae]

• Opinion
  • Not to apply
• Reason
  • Hard to apply to upstream, because upstream has their kms(tmkms)
  • We can replace ours with tmkms

[zemyblue]

We need to apply Finschia/finschia-sdk#821 in cosmos-sdk

[zemyblue]

As far as I know, Ostracon#417 is a PR to add test code of common kms of tendermint. So I think it would be nice to apply it to cometbft.

[zemyblue]

We cannot show the validator information as cli when the validator use KMS. Because createAndStartPrivValidatorSocketClient of node cannot access it in external.
https://github.com/cometbft/cometbft/blob/3b1cdce4242a67c16e8f88e4aed0fbe17d0989e0/node/setup.go#L614

So, I think it's nice to change to public function in cometbft.