Add test for ConfigurationWatchList.getCopyOfFileWatchList and ConfigurationWatchList.buildClone

Hey 😊 I want to contribute the following test:

Test that ((Collection<?>) (cwl.buildClone().getCopyOfFileWatchList())).isEmpty() is true when buildClone is called. This tests the methods ConfigurationWatchList.getCopyOfFileWatchList and ConfigurationWatchList.buildClone. This test is based on the test fileToURLAndBack.

Curious to hear what you think!

(I wrote this test as part of a research study at TU Delft. Find out more)