CCF: Predefined activities now available in a dropdown

Predefined activities are no longer displayed dominantly in single lines. Instead, they can now be selected via a dropdown menu. This makes the overview cleaner and hides irrelevant activities.

Note: The copy button for activities is currently not available. However, activities can be selected multiple times. An option to rename activities is coming soon.

As before, predefined standard activities are available and linked to specific emission factors. When you enter a consumption value, the corresponding emission factor is applied automatically. This significantly speeds up data entry for common use cases and reduces the time spent searching for suitable emission factors.