Bug/VENTokenView fixes

[simonsmileyandrews]

Fixed some small bugs associated with the VENTokenView View wouldn't resize properly when tokens were added (due to incorrect constraints) View didn't allow users with duplicate names (due to adding and removing name instead of users from array) TableView constraints not set properly meaning when keyboard was shown you couldn't scroll all users Some logic added to ensure the group name is hidden when adding users to a group (we will modify user view to enable detail modification)