Restructure and clean up the Default Components that come with lively

This is quite a large undertaking, but it will pay off since it will allow for faster development of new applications once the new Component Browser (#528) is available.

The structure of some of the components in IDE and and components is very convoluted, e.g., the Popup Windos have a "circular hierarchy" from a dark component to a light one and then another dark one.
This should be cleaned up.

We could also think about migrating the remaining components that are not yet implement with the new component architecture.