* removed the BlockPool type and all of the proxy functions around it - passing the chain DAG and the quarantine explicitly where appropriately - they don't need to be bundled in a type
* fixed the build after the rebase
The lack of body of `goodbye` in sync_protocol.nim was preventing
the respective LibP2P protocol to be mounted and advertised on the
network.
Adding a body fixes that, but I've also made some changes in the
P2P protocol codegen that will prevent the issue from happening
again (no body is now considered the equivalent of having an empty
body).