Use the `windows-sys` crate

[DataTriny]

Replaces the "potentially unmaintained" winapi crate by the windows-sys crate, officially supported by Microsoft.

I ran the unit tests and created a test app which iterates through the mac addresses found on my machine. Behavior of the library seem unchanged.

The only downside is that the MSRV of this crate is bumped to 1.60, but there is currently no policy regarding this.