feat(python): streaming larger-than-memory writes (#2094)

Makes our preprocessing pipeline do transforms in streaming fashion, so
users can do larger-then-memory writes.

Closes #2082

python/python/tests/test_embeddings.py

@@ -107,7 +107,7 @@ def test_embedding_with_bad_results(tmp_path):
         vector: Vector(model.ndims()) = model.VectorField()
 
     table = db.create_table("test", schema=Schema, mode="overwrite")
-    with pytest.raises(ValueError):
+    with pytest.raises(RuntimeError):
         # Default on_bad_vectors is "error"
         table.add([{"text": "hello world"}])