feat: add support for ravencoin

[jon4hz]

Hi, this PR adds support for ravencoin and lays the basis for other kawpow coins.

The code was tested on the ravencoin testnet.

[2023-02-14 22:57:54.7180] [I] [rvn1] Submitting block 936632 [00000003ca6b9e3312aa952d952a757705fe88e807b43b2f4cfa8a798d4da9ba] 
[2023-02-14 22:57:54.7426] [I] [rvn1] Daemon accepted block 936632 [00000003ca6b9e3312aa952d952a757705fe88e807b43b2f4cfa8a798d4da9ba] submitted by mu3CRvK5eMB3JiiNmQUwu2JLubobuhdfdb 
[2023-02-14 22:57:54.7441] [I] [rvn1] [0HMOEQPKV1L0Q] Share accepted: D=0.02 
[2023-02-14 22:57:54.7517] [I] [rvn1] Detected new block 936633 [BLOCK] 
[2023-02-14 22:57:54.7517] [I] [rvn1] Broadcasting jobs 
[2023-02-14 22:57:56.7884] [I] [rvn1] [0HMOEQPKV1L0Q] Share accepted: D=0.02 
[2023-02-14 22:58:04.2436] [I] [rvn1] [0HMOEQPKV1L0Q] Share accepted: D=0.02 
[2023-02-14 22:58:04.7487] [I] [rvn1] Broadcasting jobs 

Even though ravencoin is a fork of bitcoin, it has a different stratum protocol. This is why I added it as a custom family which extends the BitcoinJob and BitcoinJobManagerBase classes.

Payouts are handled by the BitcoinPayoutHandler without any modifications.

rel: https://github.com/oliverw/miningcore/issues/1174 https://github.com/oliverw/miningcore/discussions/876