Add cleanDiacritics function

[Shekhar Gulati]

This will be the function signature. Check if transliterate function already does this functionality.

public static String cleanDiacritics(String input)

Test cases it should pass:

cleanDiacritics("ääkkönen"); // "aakkonen"

[Shekhar Gulati]

closing this as Strman.transliterate does the job