feat: resolve peer client name via BEP 20 peer id and extended handshake

[stabldev]

Summary

Displays peer software prefixes and splits IP and Port into distinct columns in the Peers details table.

Changes

• Client Prefix Resolution:
  • Removed full-name client lookup dictionary.
  • Prefers extended handshake client string (BEP 10) if present.
  • Otherwise, directly displays the 8-character client identifier prefix encoded in the 20-byte Peer ID (BEP 20 convention, e.g. -qB4630-, -TR4050-, -UT3550-, M3-4-2--).
• Separate IP & Port Columns:
  • Added dedicated Port column next to IP in the Peers table.
  • Updated PeerInfo TypedDict with port: int.
  • Updated DownloadManager.get_torrent_peers() to parse IP address and port number separately.
• Tests:
  • Updated unit tests in test_utils_helpers.py, test_core_download.py, and test_widgets_details_panel.py.