Unify and cleanup sound related code into single sndlib module

[winterheart]

Pull Request Type

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

Description

Unify and cleanup sound related code into sndlib module. Update linux part to use SDL2 function calls instead of legacy SDL1.

Currently there two independent sound engines - sndlib and mvelib (played only on MVE cutscenes). This is major preparation before unify MVE sound related code to use single sndlib as sound back-end.

Related Issues

Related to #289

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

[JeodC]

Tested artifact in windows and sound works as expected both in movies and in levels.