Add sia-node-scanner

MERGE REQUEST

Overview

Adds a sia-node-scanner command that can be used to scan the Sia peer-to-peer network. The goal of the node scanner is to learn the IP addresses of all active Sia nodes and to attempt to connect to each of them. It logs all connection attempts and maintains a persistent set of all nodes it has ever connected to, and the timestamp of the last successful connection.

Changes to Work Flow

N/A

Testing Changes

N/A

Documentation Changes

Added README.md for the node scanner.

Modules and Packages Impacted

/cmd/

Example for Visual changes (ie Screenshot)

N/A

Issues Closed

N/A

Checklist

Review and complete the checklist to ensure that the MR is complete before assigned to an approver.

• Pipeline Passing (this is for NDFs where tests were run in a loop)
• All new methods, or updating methods have clear docstrings
• Testing added or updated for new methods
• (N/A) API documentation updated for API updates
• Module README.md updated for changes to work flow
• (N/A) Issue added to Sia-UI repo for new supporting features