enc command option

[praveensiddu]

Is your feature request related to a problem? Please describe.

If I have already entered the secret for mariadb and externalDatabase using helm vault enc and then I add a new secret nextcloud. Next time I run helm vault enc I should be able to skip mariadb and externalDatabase.

helm vault enc values.yaml
Input a value for /mariadb/db/password:
Input a value for /externalDatabase/user:
Input a value for /nextcloud/password:

Please change as follows
Input a value for /mariadb/db/password or press ENTER to skip:

Describe alternatives you've considered

Update the new secrets directly using the vault command