Embeddings API scores (#671)

- Put scores in all responses
- Remove unused 'middle' vector layer. Vector of texts -> vector of (vector embedding)

tests/integration/test_kg_extract_store_integration.py

@@ -411,7 +411,7 @@ class TestKnowledgeGraphPipelineIntegration:
             entities=[
                 EntityEmbeddings(
                     entity=Term(type=IRI, iri="http://example.org/entity"),
-                    vectors=[[0.1, 0.2, 0.3]]
+                    vector=[0.1, 0.2, 0.3]
                 )
             ]
         )