Suggestions for 813-standardize-cli

[rrybarczyk]

No description provided.

[plebhash]

we should add a new app-helpers crate to roles-utils with:

• module for arg parsing
• module for custom config deserializers
• module for parsing coinbase output

[plebhash]

@rrybarczyk FYI some PRs that could affect this one when they get merged into upstream dev:

• Handle jd-client config error stratum-mining/stratum#987
• Add JobDeclaratorClient struct stratum-mining/stratum#993

I'll keep rebasing 813-standardize-cli with those changes as they get merged