CMake: Collect used Qt modules in user projects for analytics

We should look into ways to report the used Qt modules for user projects as part of Qt Analytics (if the user allows).

Motivation

Qt Framework consists of many modules. Which of the modules are actually used by users is important for further development (both for TQtC and the community). Anyhow, this data is suprisingly hard to come by:

• We can get some data by the online installer. Anyhow, the data there is very coase (e.g. qtbase), users often install all packages 'just in case' - and finally, users get also Qt packages by other means.
• We can try to include analytics in deployment tools, like *deployqt. BUt they currently miss the infrastructure for Analytics, and are also not used everywhere.

Proposal

Goal is to let Qt Creator telemetry could start collecting the Qt CMake modules that the respective users loaded in their project: Either per project, or over time.

Questions & Challenges

• What is the best way to extract this information out of the build system? At which point?
• How will indirectly included modules be treated including Qt6Widgets automatically also includes Qt6Gui, Qt6Core?