`group` parameter for `overview_nodes` and `overview_edges`

[JabobKrauskopf]

Add a parameter to the overview_nodes and overview_edges function that is groups = GroupInputList. It returns the overview of those group only. If none specified: use all groups.

Also, important: there is no "min:" and "max:" print in prettify_table for temporal data.

                    if isinstance(info[key], float):
                        row[3] = f"{key}: {info[key]:.{decimal}f}"
                    elif isinstance(info[key], datetime):
                        row[3] = info[key].strftime("%Y-%m-%d %H:%M:%S")
                    else:
                        row[3] = f"{key}: {info[key]}"

In the datetime elif, it should have have also the key: (min or max)