Add licenses to attributions of mapbox

https://doc-snapshots.qt.io/qt5-5.9/qtlocation-index.html lists different third-party components that are potentially part of Qt Location, most of them actually from the mapbox plugin.

Anyhow, the attributions seem to be incomplete:

• Most seem to miss the actual license text (LicenseFile attribute). Note it's not enough to just give the LicenseId here.
• Please also provide the upstream version (if in any way applicable)