Move from CMake to Meson

[geniiii]

While CMake has improved a substantial amount over the last few years, it's awful for cross-compilation and still isn't all that good to write or (especially) use. Meson is the only viable alternative, besides Makefiles or a custom build system; Automake is even worse than CMake, I don't like Premake, and a build system written in Java (Bazel) isn't exactly something that appeals to me.

The only issue I can really think of here is IDE support, which is already kind of a mess anyways, due to cross-compilation and having to run the game in an emulator. This may not always be the case, as I do plan to have a PC version of 3DStris for debugging and unit testing purposes. (This is something I had already attempted previously, but CMake was a massive obstacle that led to the whole thing getting scrapped)

[geniiii]

On hold.