Fix color choice based on object ID (#32)

The data portal now also supports UniProtKB accessions as
`Annotation.object_id`. UniProtKB accessions can contain letters, so the
ID can't be directly converted to an integers anymore. This PR instead
uses `hash(Annotation.object_id.split(':')[-1])` to determine consistent
colors for annotations of the same objects.

src/napari_cryoet_data_portal/_reader.py

@@ -24,9 +24,8 @@ def _annotation_color(annotation: Annotation) -> np.ndarray:
     """Maps an annotation to a color based on its object_id."""
     try:
         object_id = int(annotation.object_id.split(":")[-1])
-    except RuntimeError as e:
-        logger.error("Failed to parse integer from object_id: %s\%s", annotation.object_id, e)
-        return DEFAULT_OBJECT_COLOR
+    except ValueError as e:
+        object_id = hash(annotation.object_id.split(":")[-1])
     color = OBJECT_COLORMAP(object_id % len(OBJECT_COLORMAP.color_stops))
     return np.array(color.rgba)