nsfs | wait for endpoint startup before namespace monitor registration

[alphaprinz]

Explain the changes

Wait for endpoint startup before registering namespace resource monitor.

Issues: Fixed #xxx / Gap #xxx

Nsr can enter "Rejected" status if endpoint is deleted by kubernetes before it is in "Ready" state. https://bugzilla.redhat.com/show_bug.cgi?id=2284585.

Testing Instructions:

Repoduction Sagie details scenario for ODS in bz.

I've reproduced with this scenario on minikube: Start with a nsfs nsr on a pvc. A single endpoint A is in "Ready" state. -Delete nsr. A new endpoint B is being spun. -While endpoint B is done creating but NOT ready yet (endpoint A is still in "Ready" state), create nsr. -Kubernetes will delete endpoint B and will leave endpoint A running. -Endpoint B loads nsr from system store, but nsr is not mounted on it. Endpoint B issues NO_SUCH_BUCKET report on nsr (and then it is deleted by kubernetes).

• [ ] Doc added/updated
• [ ] Tests added local_nsfs.yaml.txt