Port to jsonrpsee

[vorot93]

This crate was originally written in another era, when async/await and tokio were in their relative infancy, with no jsonrpc framework on top of it. It is no longer the case, with Parity's jsonrpsee now being available.

[h4sh3d]

Had a quick look at it, I think we should transition at some point to jsonrpsee but it is currently marked as Under development: The library is still under development; do not use in production. so I'd wait for there first stable release before trying to migrate. Looking at their release and TODO it should not take that long before they become stable, let see.