* [NOD-1223] Move all network stuff into a new network package.
* [NOD-1223] Delete the unused package testutil.
* [NOD-1223] Move infrastructure stuff into a new instrastructure package.
* [NOD-1223] Move domain stuff into a new domain package.
* Add Hash Writers
* Add the hash writers to the tests
* Add the DoubleHash Writer to the benchmarks
* Remove buffers from hashing by using the Hash Writer
* Replace empty slice with nil in mempool test payload
* [NOD-1220] Add network name to the version message.
* [NOD-1220] Ban peers from the wrong network.
* [NOD-1220] Add the network parameter to protowire.
* [NOD-1220] Add "kaspa-" to network names.
