This patch refactors the secret selectors to use the
`internal.cozystack.io/tenantresource` label for managing secret
visibility and removes any selectors based on it or the previous
`apps.cozystack.io/tenantresource` label, the idea being that this label
will only ever be set by the controller.
```
[controller,api] Refactor labels for the secret selector.
```
Signed-off-by: Timofei Larkin <lllamnyp@gmail.com>