[schema] Make the AnatomicPathologyReport composite of Biopsy/CellCulture/BiopsySample.

Thus, AnatomicPathologyReport is in the Subject container (defined in
medicalexp).

schema.py

@@ -78,4 +78,4 @@ class AnatomicPathologyReport(EntityType):
     description = RichString(fulltextindexed=True)
     conclusions = RichString(fulltextindexed=True)
     report_on = SubjectRelation(('Biopsy', 'CellCulture', 'BloodSample'),
-                                inlined=True, cardinality='1*')
+                                inlined=True, cardinality='1*', composite='object')