Reactivating network mtclient (Parallax Online / PXO)

[winterheart]

Pull Request Type

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

Description

Reactivating from legacy mtclient in order to enable PXO online service. Currently it's able to login tracker server with valid credentials from https://pxo.nottheeye.com/ (but unable to initialize chat server connection, need additional connection settings - server and port).

Related Issues

This PR is part of #216.

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