GitHub Actions expansion: added FreeBSD build, added few stubs for other platforms

Created by: Xottab-DUTY

The inspiration were SDL workflows, like these: https://github.com/libsdl-org/SDL/blob/main/.github/workflows/msvc.yml https://github.com/libsdl-org/SDL/blob/main/.github/workflows/main.yml

TODO: cross-compilation for Ubuntu arm64/ppc64el

TODO: add macOS multiarchitecture build: https://stackoverflow.com/questions/5334095/cmake-multiarchitecture-compilation

TODO: cross-compilation for Haiku: https://jessicah.github.io/building-rust.html https://github.com/kaidokert/scummvm-buildbot/blob/a6be13f7922466b576c998e80f9e1bf9d3a601f3/workers/haiku/Dockerfile

Track TODOs in #1403