Add loading time of plugins in the Plugin dialog

Sometimes Qt Creator takes longer to start. 

One can use qtcreator.exe -profile to find out more about this.

But Qt Creator can do this timing of loading of plugins all the time and display this information in the Plugins dialog.

This way I could easily see which plugin takes time to load. Android, WebAssembly, Docker ...

There could also be a threshold and if a plugin is over that Qt Creator could display that information to the user.

It might be that users install EVERYTHING from a Qt Version, because it's convenient, and get slowed down due to things that they don't use.