Store Secrets on a Per-System Basis

[Sneagan]

Rather than storing all secrets in one file, store them in separate files on a per-system basis. For example, a separate file for Zebpay and Solana secrets. This is separate from the storage of chain signing keys, which are already stored separately and should remain so. Perhaps make it such that the signing key is added to an existing system file if it exists or into a new one if it doesn't so that system secrets can share a file with signing keys. This will change both storage and retrieval of these secrets and will impact both tooling to persist, the enclave retrieval, and disaster recovery tooling.