cli: Add AuthorityCheck command to ensure validators are reachable via DHT records

[lexnv]

This PR ensures all addresses of validators are reachable after discovering them on the DHT.

• Provides insights into addresses unreachable, DHT records missing and validator availability
• Ensures that DHT records are scraped faster, up to 7x times by forcing multiple queries in parallel
• An extra CLI option is added to propagate the full output of the command in JSON file (for other services to showcase the data)