fix visualization functions for the new node types

[Mayur1009]

Update the visualization function to work with the newly added node types.

• tm.py: map_ta_id_to_feature_id didn't treat AND_ALTERNATIVES as feature-sharing (only OR_ALTERNATIVES was).
• utils.py: active_path_graph returned class_sums[0] instead of class_sums[:, 0].
• utils.py: node-type labels (used to be strings, now ints) restored via a node_type_labels dict param, with defaults and per-key overrides.