Parses the date given in parameter. The date format should comply to ISO-8601 standard. The string may contains either a single date, or a
start time, end time and a period. In the first case, this method returns a singleton containing only the parsed date. In the second case, this
method returns a list including all dates from start time up to the end time with the interval specified in the value string.
value - The date, time and period to parse.
A list of dates, or an empty list of the value string is null or empty.