Add jsonrpsee client

[OverOrion]

No description provided.

[OverOrion]

Long story short the issue is that the JsonrpseeClient::new() function is calling an async private function (e.g., async new) in the background, but this function already gets called in a block_on fashion, so a panic happens:

thread 'tokio-runtime-worker' panicked at 'cannot execute `LocalPool` executor from within another executor: EnterError', /opt/rust/registry/src/github.com-1ecc6299db9ec823/futures-executor-0.3.28/src/local_pool.rs:81:26

The substrate-api-client master has this issue fixed as the async constructor is public, but that commit was not backported to the .39 branch. Needless to say the moment an async function needs to be called then that async qualifier spreads like a virus, meaning that it would infect many parts of the codebase. To mitigate this I think a new entity which starts a new thread then runs the needed constructor should solve it. As easy it sounds it gets complicated because of the tokio runtime, which needs that the thread is not a simple std::thread, but a tokio one which has the necessary runtime in it.

I am currently working on this, will see tomorrow how it goes.