Add API to cancel sync jobs

[jingtang10]

Is your feature request related to a problem? Please describe.
The sync jobs are identified by the fhir sync worker class at the moment. but maybe it would be a good idea to create an id that can be used to cancelling the job.

Describe the solution you'd like
add a new id to identify jobs - so that we can have unique jobs even if they reuse the same fhir sync worker. and that id can be used to cancel jobs.

Describe alternatives you've considered
NA

Additional context
NA

Would you like to work on the issue?
@santosh-pingle

[jingtang10]

@aditya-07 @MJ1998 fyi