Add support for HCP Vault SaaS

[huewood]

Hi there 👋

Would it be possible to add support for the SaaS product instead of self-hosted/dedicated version?

https://developer.hashicorp.com/hcp/docs/vault-secrets

Thanks!

[jeremybumsted]

Hey @huewood ! Thanks for raising this!

Definitely something we'll want to add - looks like there is a move to use the HCP cli so we'll need to ensure parity between the old vault cli and this new CLI tool.