Reactivate Gamespy functionality

[winterheart]

Pull Request Type

• [ ] GitHub Workflow changes
• [ ] Documentation or Wiki changes
• [ ] Build and Dependency changes
• [x] Runtime changes
  • [ ] Render changes
  • [ ] Audio changes
  • [ ] Input changes
  • [x] Network changes
  • [ ] Other changes

Description

This PR reactivates GameSpy protocol support which is still used for tracking dedicated servers. Tested on Masterserver-Qt5 tracker instance. Still there need more testing with real trackers in the wild internet.

There need also game browser which query trackers for available servers.

Related Issues

Partially implements #541.

Screenshots (if applicable)

Checklist

• [x] I have tested my changes locally and verified that they work as intended.
• [x] I have documented any new or modified functionality.
• [x] I have reviewed the changes to ensure they do not introduce any unnecessary complexity or duplicate code.
• [x] I understand that by submitting this pull request, I am agreeing to license my contributions under the project's license.

Additional Comments

[DoCheckor]

Brilliant! Can't wait! BTW: Descentforum.net is hosting a dedi on Win now. Available through tsetsefly.de tracker which is the one the D3 1.4 Community is using...