Write a Python program that prompts the user to input a list of strings, and then returns the longest common suffix of the strings in the list. Your program should handle an arbitrary number of strings, and should output "None" if there is no common suffix. Furthermore, your code should not rely on any external libraries or modules, and should utilize functions and control structures appropriately. Make sure to use descriptive variable names and include comments where appropriate. Lastly, test your program with at least three different test cases to ensure it functions correctly.
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