[Python] Default PYARROW_CMAKE_GENERATOR can yield broken libraries with MSVC if the C++ toolchain is different

[asfimport]

See discussion in #6350.

Python's setup.py defaults to the "Visual Studio 14 2015 Win64" CMake generator here

https://github.com/apache/arrow/blob/apache-arrow-0.16.0/python/setup.py#L130

We found in ARROW-6757 that if VS 2017 or newer was used to build the C++ libraries, then there can be a toolchain conflict causing segfaults. I'm not sure if there's a better way to infer which VS toolchain is "preferred" (based on what "VsDevCmd.bat" was run), but we should see if we should do something other than what we have now

Reporter: Wes McKinney / @wesm

Related issues:

• [Python] Creating csv.ParseOptions() causes "Windows fatal exception: access violation" with Visual Studio 2017 (is related to)

_{Note: This issue was originally created as ARROW-7769. Please see the migration documentation for further details.}