Support sending gzipped request body

[anchita-g]

Is your feature request related to a problem? Please describe.
To optimise for networks bandwidth, it would be good to support gzipping the HTTP request body in FHIR Engine

Describe the solution you'd like
Have an option to automatically gzip the HTTP request body. This should be optional as the server might or might not be able to understand the compressed request body.

Describe alternatives you've considered
No other alternatives for this

Would you like to work on the issue?
If bandwidth allows

cc: @jingtang10

[santosh-pingle]

@anchita-g
Are you going to work on this issue?
(If yes, please add priority and effort to fix this issue.)