In top right corner when in a List view you'll be finding manage list menu. This now have an added option to copy current list uuid to clipboard.
In top right corner when in a Package view you'll be finding publish options menu. This now have an added option to copy current package uuid to clipboard.
If you want to copy a list uuid from within Package view, you'll be able to reach that functionality by accessing the internal list menu in top right of the list view part.
