Anton/sync groups and verticals

This fixes https://openedx.atlassian.net/browse/BLD-1095

NB: before merge `ENABLE_GROUP_CONFIGURATIONS` should be set to default value.

Please review: @tymofij  @cahrens 
I encourage you to look for a design that doesn't rely on storing the name in two different places and keeping them in sync.

The method that you're using here, of synchronizing them whenever the split test renders, will result in many more updates to the contents than are actually required.