Static build package in Qt installer

I suggest adding a Static prebuild of Qt to the offline/online installer, mainly for MinGW. Qt docs lacks information about building Qt statically, also, there are no full-complete examples. A static build has many advantages, mainly on Linux, As it's an offline installer I think that the size is not a big problem. You can document the issues with the static build so the developers know in which circumstances it can be used. I haven't managed to build Qt Quick Controls 2 statically for Windows platform as the graphics are off in the QTQC2 UI for this kind of builds. Also, the Material style crashes.

PD: My best result building a Static Qt on Windows:

`configure -prefix "C:/somePath/QtStatic" -static -static-runtime -release -opensource -confirm-license -qt-zlib -qt-pcre -qt-libpng -qt-libjpeg -opengl desktop -sql-sqlite -qt-freetype -make libs -make tools -nomake examples -nomake tests -skip qtwebengine`