Add Qt KNX and QtMQTT to the marketplace.
The idea is to distribute these in the Qt Online Installer to provide the same user experience like today.
The installer uses Qt version-specific installer repository, which makes these dependent on Qt releases. For KNX and MQTT the repository structure must be changed to allow installation of either protocol separately. Using the current repository, purchasing one item would result in all four M2M protocols be available for the user in the marketplace.