ecctl deployment delete output is unhelpful on ESS

[gtback]

Readiness Checklist

• I am running the latest version
• I checked the documentation and found no answer
  The documentation does explain it, but I think the tool itself could be more intuitive
• I checked to make sure that this issue has not already been filed
• I am reporting the issue to the correct repository (for multi-repository projects)

Expected Behavior

If I run ecctl deployment delete against an ESS deployment, I should get a message saying something to the effect of:

ecctl deployment delete is for Elastic Cloud Enterprise only. For Elasticsearch Service (cloud.elastic.co), did you mean to use ecctl deployment shutdown?

Current Behavior

$ ecctl deployment delete <MY-DEPLOYMENT-ID>
[DELETE /deployments/{deployment_id}][404] deleteDeploymentNotFound  &{Errors:[]}`. 

The help text for this command does help (assuming I know what ECE is):

$ ecctl deployment delete --help
Deletes a previously shutdown deployment (Available for ECE only)

Usage:
  ecctl deployment delete <deployment-id> [flags]

Flags:
  -h, --help   help for delete

...

Steps to Reproduce

1. Create a deployment in ESS
2. Run ecctl deployment delete <THE-DEPLOYMENT-ID>

Possible Solution

Alternatively, this could just do The Right Thing ™️ and shutdown/delete the deployment.

Context

I was trying to delete a deployment I had just created in ESS (where the related UI text says "Delete deployment") and using the shell completions showed there was an ecctl deployment delete command, when I should have used ecctl deployment shutdown.

Your Environment

• Version used: v1.5.0
• Running against Elastic Cloud SaaS or Elastic Cloud Enterprise and version: ESS
• Environment name and version (e.g. Go 1.9): go1.16.7
• Server type and version: N/A
• Operating System and version: macOS
• Link to your project: N/A

Version:               v1.5.0
Client API Version:    2.11.0
Go version:            go1.16.7
Git commit:            39dffeee
Built:                 Wed 18 Aug 13:33:30 2021
OS/Arch:               darwin / amd64