FR: Add cmctl (from certmanager) utility for certificate management

[salami738]

At first: thanks for creating cloudcontrol. It is useful for us!

I would like to suggest the cmctl tool for integration into cloudcontrol.
Source: https://cert-manager.io/docs/reference/cmctl/

This makes it much easier, for example, to renew letsencrypt certificates before they expire.
Example:

./cmctl_linux_amd64 renew -n myNamespace myCertificateName
Manually triggered issuance of Certificate myNamespace/myCertificateName

[dploeger]

Released in 7.0.0