Add workspace:delete command to delete user's workspace

[tolusha]

Is your task related to a problem? Please describe.

User might work and then go which make his workspaces abandoned. Admins needs a tool to cleanup user's resources.

Describe the solution you'd like

Add workspace:delete command to delete user's workspaces.

Describe alternatives you've considered

Additional context

Check how it works with per-namespace strategy.
downstream issue https://issues.redhat.com/browse/CRW-538

[sleshchenko]

@tolusha Could you clarify more about this command?
Is it going to have different flags like

chectl workspace:delete // non-valid
chectl workspace:delete --all-workspaces //delete all available workspaces of the current user
chectl workspace:delete sleshche/java-mysql //delete workspace `java-mysql` of the user `sleshche`
chectl workspace:delete --all-users //delete all workspaces on the Che cluster. Available only for Che Admin

[tolusha]

[16:49:30] tolusha@fractal ~/projects/chectl/bin (ab/delete) $ ./run workspace:list -n abazkoche --access-token=$CHE_ACCESS_TOKEN
  ✔ Verify Kubernetes API...OK (it's OpenShift)
  ✔ Verify if namespace 'abazkoche' exists
  ✔ Retrieving Eclipse Che server URL... http://che-abazkoche.apps.ocp43.codereadyqe.com
  ✔ Eclipse Che status check
  ✔ Get workspaces... done
Id                        Name                 Namespace Status  Created                  Updated 
workspace55z6ay05muvv3wk1 apache-camel-k-qwn6g admin-che STOPPED 2020-03-18T14:45:55.177Z         
[16:49:42] tolusha@fractal ~/projects/chectl/bin (ab/delete) $ ./run workspace:delete -n abazkoche --access-token=$CHE_ACCESS_TOKEN -w workspace55z6ay05muvv3wk1
  ✔ Verify Kubernetes API...OK (it's OpenShift)
  ✔ Verify if namespace 'abazkoche' exists
  ✔ Retrieving Eclipse Che server URL... http://che-abazkoche.apps.ocp43.codereadyqe.com
  ✔ Eclipse Che status check
  ✔ Get workspace with id 'workspace55z6ay05muvv3wk1'... done
  ✔ Delete workspace with id 'workspace55z6ay05muvv3wk1'... done
  ✔ Verify if user namespace exists 'admin-che'... not found
  ↓ Delete user namespace [skipped]