refactor sorting for date, add class "asc" or "dsc" for reverse

convert date string to date obj when sorting, so it can sort correctly
refactor sortBy method, add helper predicateConverter

- currency in json is a now a string. Make it easier for filtering the
value
- update randomize data to format accumulationAnnuitizationValue as
currency
Merge pull request #3 from lvo811/update-sorting

refactor sorting for date, add class "asc" or "dsc" for reverse