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.

First phase reviews: @tymofij  @olmar 
That will not work in some cases. 
For example, when you have group that was removed from group configurations, it will displayed as not active group in studio view for split test. But name for that group is not saved inside user_partitions, as it was removed from there.