Add support for Scash

[bitcartel]

Scash is a newly launched network: https://s.cash , https://twitter.com/scashnetwork

There is currently no mining pool support, so would be great if nanopool could add support. Miners discord channel: https://discord.com/invite/T4Jcw2c95V

PoW being used is RandomX v1.2.1 with commitments, where the commitment value must meet the block target. Details are in protocol spec here: https://github.com/scash-project/sips/blob/main/scash-protocol-spec.md

There is a cpuminer available here: https://github.com/scash-project/cpuminer-scash/

If needed, available to help implement and test. Thanks!