Correctly compile libicu on Windows

[mgautierfr]

Working on Windows compilation, I have succeed to compile libicu on Windows with meson provided on https://mesonbuild.com/Wrapdb-projects.html

This seems to be ok, but libkiwix tests was failing about translation of languages.
Moving to prebuild icu on Windows fixe the tests so I suspect issue with icu data.

But doing so, we now have icu dll to distribute with our binaries.

We should investigate that and compile correctly icu statically.