Network protocol is outdated: pruned node services

This is a port of issue https://github.com/bcoin-org/bcoin/issues/721

Most importantly, it prevents pruning nodes from broadcasting blocks and that also includes MINERS that are using pruned nodes:

https://github.com/handshake-org/hsd/blob/1a086e44b5b60e1ebb01955b0e1b2a0ebd00b42d/lib/net/pool.js#L1146-L1159

We can adopt [BIP159](https://github.com/bitcoin/bips/blob/master/bip-0159.mediawiki) which adds a service bit to the protocol to signal a node has limited blocks to share.