Library building for Windows compilers

[partouf]

Part of #1332

Will need to address the following:

• Building with CMake on Windows
• Building with MingW compilers
• Building with MSVC compilers
• Sending packages to Conan
• Whatever else comes up

Will not include (things to be added later):

• Windows builder packer image
• Infra setup for Windows builder
• Non-C++ stuff

[partouf]

Does not introduce a new LibraryBuilder class in order to reuse as much as possible from existing (proven) code

[partouf]

msvc builds done, now remains only conan stuff which is probably the hardest

[partouf]

TODO

• Copy some extra files to Win SDK directory

[partouf]

Am at a a bit of deadlock now. Will write it down in the hopes that I miraculously think of the correct solution.

The problem:

When building the libraries for Windows, I force the recipe for conan to be a 'package install' which means it packages the install directory and you say to cmake hey install it to that directory.

This is done to avoid having headers on disk permanently like we have for most of our Linux libraries.

But the consequence of that is that the conan recipe changes, and that's replaced on the conan server for that library version.

Now, technically, CE doesn't actually use the recipes. It's only for telling conan what to zip up and upload. But if the recipe is changed, will it also say it needs reuploading for compilers that already have an upload? I need to figure this out first. I think I can check this by uploading a msvc build and then try to upload a build for a gcc that we've already done in the past. But I do need to disable force uploading before I do that.

Doing that now before continuing this writeup.