feat(cli): reorganize attached integrations

[migmartri]

Attached integration-related commands were placed under workflow namespace.

This patch moves all those commands under integration attached ns. This makes it consistent with the rest of the integration-related commands and their life-cycles.

It also delete dependency-track commands since in the end by adding these namespaces we broke compatibility. I'll update the guides next.

$ go run main.go --insecure integration                                    
Third party integrations

Usage:
  chainloop integration [command]

Available Commands:
  attached    Integrations attached to workflows
  available   Integrations available in the controlplane ready to be registered
  registered  Integrations registered and configured in your Organization

Attached

$ go run main.go --insecure integration attached
Integrations attached to workflows

Usage:
  chainloop integration attached [command]

Available Commands:
  add         Attach an existing registered integration to a workflow
  delete      Detach an integration that's attached to a workflow
  list        List integrations attached to workflows

Registered

$ go run main.go --insecure integration registered
Integrations registered and configured in your Organization

Usage:
  chainloop integration registered [command]

Available Commands:
  add         Register a new instance of an integration
  delete      De-register an integration
  list        List registered integrations

Available

$ go run main.go --insecure integration available 
Integrations available in the controlplane ready to be registered

Usage:
  chainloop integration available [command]

Available Commands:
  describe    Describe integration
  list        List available integrations

[danlishka]

LGTM!