Add hover interactions to column chart
Add hover interactions to column chart

Implement hover interactions similar to the hover-line behavior for
column charts that highlights the current column and displays
its labels

unicef/polio,SeedScientific/polio,unicef/rhizome,unicef/rhizome,SeedScientific/polio,unicef/polio,unicef/rhizome,SeedScientific/polio,unicef/rhizome,unicef/polio,unicef/polio,SeedScientific/polio,SeedScientific/polio