is_edge_attr_match fails on attribs other than labels

the function _is_edge_attr_match doesn't work on any other attributes other than __labels__

This is due two the _aggregate_edge_labels

```python
motif_edges = _aggregate_edge_labels(motif_edges)
host_edges = _aggregate_edge_labels(host_edges)
```

After the calls, motif_edges and host_edges only have __labels__ attributes left, and other attribuets are dropped.

```python
def _aggregate_edge_labels(edges: Dict) -> Dict:
"""
Aggregate '__labels__' attributes from edges into a single set.
"""
aggregated = {"__labels__": set()}
for edge_id, attrs in edges.items():
if "__labels__" in attrs and attrs["__labels__"]:
aggregated["__labels__"].update(attrs["__labels__"])
elif "__labels__" not in attrs:
aggregated[edge_id] = attrs
return aggregated
```