[osqp] Add new port

[ex-purple]

• Changes comply with the maintainer guide.
• The name of the port matches an existing name for this component on https://repology.org/ if possible, and/or is strongly associated with that component on search engines.
• Optional dependencies are resolved in exactly one way. For example, if the component is built with CMake, all find_package calls are REQUIRED, are satisfied by vcpkg.json's declared dependencies, or disabled with CMAKE_DISABLE_FIND_PACKAGE_Xxx.
• The versioning scheme in vcpkg.json matches what upstream says.
• The license declaration in vcpkg.json matches what upstream says.
• The installed as the "copyright" file matches what upstream says.
• The source code of the component installed comes from an authoritative source.
• The generated "usage text" is accurate. See adding-usage for context.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is in the new port's versions file.
• Only one version is added to each modified port's versions file.

[ex-purple]

I don't know what the problem is with Windows builds

[WangWeiLin-MV]

Please check the logs page or download logs from here.

[ex-purple]

Yes, I've already looked. It's not clear to me

[data-queue]

It's also not immediately clear to me why this port is failing on Windows either, maybe we can do supports: !windows in the vcpkg.json to move this PR forward?

[dg0yt]

multiple rules generate out/osqp.lib

on Windows/MSVC

Guess: One rule for static lib, one rule for import lib.

And indeed, CMakeLists.txt wants you to set OSQP_BUILD_SHARED_LIB and OSQP_BUILD_STATIC_LIB.
https://github.com/osqp/osqp/blob/ff371613bef82e85fb431590343853846ff96203/CMakeLists.txt#L59-L60

And vcpkg wants this for all triplets.