Adds a new module server_group which adds a new plugin to override full view
mode for group node content type.
Plugin class is NodeGroup.
All the configs are pushed to default sync folder.
Test ServerGroupTest is added to validate the logic.
Adds a new template server-theme-person-card and a new method getPersonCards
in StyleGuideController to invoke this. I have not added a new card grid to be
able to use existing server-theme-cards to display a grid of those.