Build: CMake as building system

[metaq3]

As the title says, it replaces Makefile that has been used for building this mod. It also contains some features, that were not present in Makefile:

• Changing header file leads to recompilation of files that include it.
• • QVM recompiles all source files, though, but only on header change. Modifying .c files make only changed files to recompile.
• Undefined symbols now are disallowed during native library building. This ensures that game modules load successfully when using native build.
• Multi-threaded support, providing faster build times.
• Tests do not require Catch2 pre-installed. It's rather built automatically.

CI for Windows is separated into MSVC and MinGW parts. MSVC support would be nice!

I also updated the README. It should be prettier now. You can also checkout release from my repo to see how it goes.

You're free to squash commits when merging, as they do not represent great history. Waiting for your review!

[snems]

Good job, thank you!