Add refresh policy to CRUD APIs

[qreshi]

Is your feature request related to a problem? Please describe.
Notification integration tests are flaky as sometimes operations are done to create/delete and then retrieve Notification configs which don't alway reflect the changed state.

Describe the solution you'd like
The CRUD API for Notification at times may be used to change state of the underlying documents and then be retrieved with a short turnaround time to retrieve the changed state. Allowing to pass in ?refresh=true to ensure refreshes on the Notification config index after such operations could be useful for this.

Describe alternatives you've considered
For the flaky tests in particular we could add a longer Thread.sleep (which are already present) but this is hacky and should be avoided when an internal mechanism exists.

Additional context
Add any other context or screenshots about the feature request here.

[Hailong-am]

duplicate with #790, will track by #790