Importing Quizzes in Teams

I doubt that there is a quick and easy way. Forms quizzes in Microsoft Teams is a very rudimentary app. That is probably the trade off of having a modern, light, agile app like Teams. It is easy to learn and use but limited. Don't expect to have the same set of features that you have in Moodle otherwise you are going to be very disappointed. Ms Teams is 'newer' but 'better' depends on your application. I would say that it is easier to implement and easier for teachers to use and ticks all the essential boxes. It integrates all modes of communication but when it comes to assessments, quizzes and the like, Moodle has a much richer feature set.