This PR replaces the existing RPC snooper with a new one.

The existing snooper unfortunately causes several problems when
intercepting CL<>VC connections.
This is due to lack of proper support for the event stream calls. 
These event stream calls are currently timing out after roughly a minute
and do not serve any events.

The new snooper properly handles event stream calls and adds the invoked
events to the log output.
Besides of that it supports all the common snooper functionality.
It logs prettified JSON and hex encoded SSZ bodies as usual.
Co-authored-by: Barnabas Busa <busa.barnabas@gmail.com>