CI Windows

Enable Windows jobs compiled for Win10 and Win8.1

Includes steps prepare, build, test and package.

A few modifications made outside CI:

• Fix stack size for Radiometry test (because of 6s)
• Avoid using _findfirst and _findnext as they belong to windows internals, they are not usable on Windows Server 2016
• When using GDAL memory dataset (vectorization & rasterization): use the proper cast for buffer pointer, previous code was crashing on Windows Server 2016
• Version tag was omitted in otb::StandardShader (causes a crash with Mesa OpenGL)
• Fixes on selftester scripts
• Fixes in OpenCV superbuild, control what is built