feat: add DHT Node example with better message visualization

[MiguelMedeiros]

Enhanced the node example with better formatting and more detailed statistics:

• Added colored output for better readability
• Improved DHT size estimation display with proper percentage formatting
• Added structured message logging with clear message types (find_node, get_peers, etc)
• Included basic node information display (ID, addresses, firewalled status)
• Added message type explanations in trace logs

The example now provides a clearer view of DHT node operations and network statistics.

Usage

Run the example with:

RUST_LOG=trace cargo run --example node

This enhancement makes it much easier to:

• Monitor DHT network activity
• Debug message flows
• Understand node interactions
• Track network size and health
• Visualize message patterns