Setuptools compatibility and Windows fixes

[mstimberg]

This replaces msvc.msvc14_get_vc_env (the msvc module has been removed from setuptools in version 74), by distutils._msvccompiler import _get_vc_env, which appears to work as a drop-in replacement. IIUC, the setuptools.msvc added a bit of functionality for newer compilers compared to the support in distutils, but those changes have been contributed to distutils since. This is maybe not the cleanest solution (_get_vc_env is not really meant for public use), but the distutils infrastructure is meant to be used for building Python extension packages, not for generating code at runtime, so we'll always have to work around its limitations a bit.
Speaking of which, this PR also fixes a few issues that I noted during testing on my Windows VM, most importantly quoting include/library directory names.

CC @bvogginger, @neworderofjamie

Closes #1557

[neworderofjamie]

I agree that, with setuptools 74, this is probably the solution but, what if the distutils version is from before the setuptools.msvc functionality was back-ported (I'm not 100% sure what the timescale of that process was)? I was thinking of doing something like:

try:
    from setuptools.msvc import msvc14_get_vc_env as _get_vc_env
except ImportError:
    from distutils._msvccompiler import _get_vc_env

[mstimberg]

You are right, this would be better. BTW, 0.74.1 is out, and it reverted the change to remove the msvc module, so at least builds on Linux and macOS should no longer break. It does still remove the function we used, though.

[mstimberg]

IIUC, the setuptools.msvc added a bit of functionality for newer compilers compared to the support in distutils, but those changes have been contributed to distutils since.

Just to clarify this (I misunderstood initially): the changes from setuptools weren't contributed to the standard library distutils, but to setuptools.distutils – if you import setuptools, importing distutils will actually import setuptools.distutils.