we want to move to newer version of JsonRpc (2.x) from 1.x we use.

but that has some complexity since version 2.x and 1.x is incompatible and we let partner to directly access Rpc exposed from ServiceHubServiceBase type.

this is first step so that partners move to new API that doesn't expose JsonRpc directly.

once they moved, moving us to new versino should be easier since we will not break partner teams.