feat: provide an option to deploy private services

[zaremba-tomasz]

TODO:

• flag value is not loaded properly from the persisted config file
• flag location might be something worth discussing
• compilation issue after rebase on latest main

Testing

Should output the knative manifest without labels

go run main.go deploy --dry-run

Should output the knative manifest with a labels with value cluster-local

go run main.go deploy --dry-run --private

Similarly you could generate the config with and run deploy to get a similar output:

go run mian.go init config --private --persist
go run main.go deploy --dry-run