Set `group_info.group_label` to the displayed group label

[juleswg23]

Instead of #755, we can assign group_info.group_label to have formatted/relevant text for display. At the moment it is always None.

When that is done, group_label = group_info.defaulted_label() will get the correct label, and we won't have to implement this workaround.

Solving this issue should also resolve #236

Originally posted by @juleswg23 in #755 (comment)