Create a separate legal page in Qt Reference

Hei,

Re: https://doc.qt.io/qt-6/licensing.html

The "Qt Licensing" page is supposed to be about licensing Qt, but recently, I've added links to the SBOM and in the future, a link to export controls. Qt Licensing is mostly about the differences in the Qt licensing model (commercial vs. open-source) and some links to the licenses we used.

Should we continue adding things to the Qt Licensing page or should we spin off a separate page for legal disclaimers, compliance, and those things? Security is also under compliance, but has links from other places. I think it is time to have a legal page to collect these links.

I assigned to kkohne because he can make the decision if we need it.