Fix support for building on Windows with Ninja

[traversaro]

Fix #1083 .

To do so, it was necessary to fix support for building shared libraries and disabling static libraries in osqp 0.6.3, this was already done since a lot of time in osqp master, but as long as we do not get a release of osqp, we continue to use osqp 0.6.3 . The related commits are:

• robotology-dependencies/osqp@060751f
• robotology-dependencies/qdldl@3770026

[traversaro]

For now I will not update the docs, as anyhow ninja + superbuild has its own problems (see https://discourse.cmake.org/t/efficiency-issues-with-externalproject-sub-builds-under-ninja and https://gitlab.kitware.com/cmake/cmake/-/issues/22145), but it may be useful to know this for faster builds on Windows, fyi @S-Dafarra @mebbaid or anyone else that actually uses the superbuild on Windows (not sure who).

[traversaro]

At least in CI, Ninja builds take ~half of the time of Visual Studio builds.