New build system + fix windows

[tadeas-hejnic]

Create a new build system or edit the current script build_resolver.py based on this comment:

• usd_root variable seems redundant.
• the return values fail on my side on windows as my paths contain spaces. solution for it was to add double quotes.
• there's no consistency in computing the paths, we use fstring with one and os path join with the other.

    houdini_cmake_path = f"{root}/toolkit/cmake"
    python_exec = os.path.join(root, "python", "bin", "python")
    return [
        "-DBUILD_TARGET=houdini",
        f"-DUSD_ROOT=\"{root}\"",
        f"-DCMAKE_PREFIX_PATH=\"{houdini_cmake_path}\"",
        f"-DPYTHON_EXECUTABLE=\"{python_exec}\"",

Originally posted by @MustafaJafar in #46 (comment)

Fix it also for windows.