MSVC: do not build fuzz/ and style/ tests on Windows
MSVC: do not build fuzz/ and style/ tests on Windows

Stuff like `waitpid` is a sure sign that `fuzz/` is better skipped when
building on Windows. The `style/` is about compiling like C++ and about
making sure that all files which need some functions include `compat.h`.
I don't feel like researching how to do `-Werror=c++-compat` on MSVC,
and if the `compat.h` is ever missing, the MSVC build will yell loudly.

CESNET/libyang,CESNET/libyang