[Server][FaceRest] Be serverIdDataIdHostgroupIdVectorMap to private
variable.
[Server][FaceRest] Add a new member variable: serverIdDataIdVectorMap

And, use Pimpl idiom.
[Server][FaceRest] Add a new function: addAlreadyAddedJsonData
[Server][FaceRest] Add a new function: isAlreadyAddedJsonData