Add QT proprietary versions for Linux to Dockerfile and docker image
Add QT proprietary 5.15.14, 5.15.19, 6.8.1, 6.8.3 in Dockerfile, and uses an entrypoint script to configure them instead of using qtchooser (because qtchooser doen't work for proprietary versions).
Split opensource versions from proprietary versions by using a different directory.
Edited by Peio Rigaux