Class for reference: https://www.cs.colorado.edu/~main/edu/colorado/nodes/CharNode.java

Task 2: Use a linked list of characters to represent DNA. Use CharNode.java (link above) implementation of a node for a linked list with char data in each node. Write a method that takes a String and converts it into a linked list of characters. The header of the method is the following:

public static CharNode stringToList(String userDNA)

If the string is empty then the method should return null. Your program should prompt the user to enter a DNA strand and use this method to convert the string user entered into a linked list of characters.