1. Extending templater with kyaml functions and creating combined catalogue
to be able to request/update the existing resources.
This is based on 'everything is transformer' concept introduced in kustomize 4.x
That includes gathering all secrets into 1 variable catalogue and
special mechanism to regenerate/merge with manual secrets.
2. Implementing 'catalogue per cluster' approach for secrets.
3. Rearranging secrets so it's possible to use:
pgp (each person may have his own key), age, Hachicorp Vault and etc
and the list of people who can decrypt documents is set in a special file.
Since in some cases there should be a separate list of people who can decrypt
data - this list is set for each cluster (ephemeral and target) separatelly.
Closes: #586
Change-Id: I038f84dd138d5ad4a35f4862c61ff2124c2fd530