Parity Ethereum 2.0.0 (#9052)

* parity-version: major bump to 2.0.0 🎉

* parity-ethereum: rename crate 🌵

* ethcore: only accept service transactions from parity-ethereum nodes

* parity: fix --identity tests

* rpc: fix sync provider in tests

* rpc: fix parity_net_peers test

* ethcore-sync: accept service transactions from parity and parity-ethereum

* ethcore-sync: fix indentation

* ethcore-sync: split the ifs to reduce code redundancy

* ethcore-sync: fix syntax

* Fix building ethcore

* update cargo.lock

* parity-version: major bump to 2.0.0 tada

* fix merge