Add test for secret-list

```
  NAME
    secret-list - list secrets

  SYNOPSIS
    secret-list [--ephemeral] [--no-ephemeral] [--private] [--no-private]

  DESCRIPTION
    Returns a list of secrets

  OPTIONS
    --ephemeral      list ephemeral secrets
    --no-ephemeral   list non-ephemeral secrets
    --private        list private secrets
    --no-private     list non-private secrets
```
depends on https://github.com/autotest/virt-test/pull/1626