Compound/templated/macro secrets

[synergiator]

Describe the solution you'd like
I would like to be able to have a possibility to reference secrets from other secrets.

That is, you could reuse a secret in some context. E.g. imagine you have a service which owns a configuration consisting of dozens of secrets; you could put up them as dozens of variables, but with the new feature you would conjure up their combination as single secret by referencing.