Allow for synchronous creation of a binding

[rhuss]

Waiting for a binding to be ready would be nice, much like kn service create does:

kn service create edisplay --image gcr.io/knative-releases/knative.dev/eventing-contrib/cmd/event_display
Creating service 'edisplay' in namespace 'default':

  0.034s The Route is still working to reflect the latest desired specification.
  0.048s Configuration "edisplay" is waiting for a Revision to become ready.
  0.072s ...
 13.932s ...
 14.002s Ingress has not yet been reconciled.
 14.042s Waiting for load balancer to be ready
 14.213s Ready to serve.

Service 'edisplay' created to latest revision 'edisplay-00001' is available at URL:
http://edisplay.default.example.com

And maybe add some summary message at the end.

Also, these options would be helpful then

      --wait                              Wait for 'service create' operation to be completed. (default true)
      --wait-timeout int                  Seconds to wait before giving up on waiting for service to be ready. (default 600)

(and --no-wait for an aync operation as it is now)

[rhuss]

This would help in detecting errors, like misspelled sink names, as there seems to be no validating webhook on the operator that could detect such an error during creation time.

With a sync operation one could detect the error state and report it back to the user.

[github-actions]

This issue is stale because it has been open for 90 days with no
activity. It will automatically close after 30 more days of
inactivity. Reopen the issue with /reopen. Mark the issue as
fresh by adding the comment /remove-lifecycle stale.

[rhuss]

/approve
/lgtm

[rhuss]

/remove-lifecycle stale