#1374 - fixed viewport reset under 20 items
#1376 - create the sort order panel + script to switch between sort/locations
#1376 - populate sort options in the side panel
           - create callback and reload data from CKAN
#1376 - implement keep location selection in the side panel when sorting changes
#1376 - update sorting options
Merge pull request #1410 from OCHA-DAP/arti-sprint-34

Implement sorting panel