Description: Returns addToFile paramters from the given sources list as an associative array, where file name and file contents are seperated.
Parameter:
sourceName: The name of the package source list
Returns:
: Associative array with file name and file contents (e.g. [0] = Array ([file] = file1.txt, [text] = text1), [1] = Array ([file] = file2.txt, [text] = text2), ...)