Port validation benchmark

From src/validation/__tests__/validateGQL-benchmark.js

Author: ktosiek

tests/benchmarks/test_validate_gql.py

@@ -0,0 +1,12 @@
+from graphql import build_schema, parse, validate
+from graphql.utilities import introspection_query
+
+# noinspection PyUnresolvedReferences
+from ..fixtures import big_schema_sdl  # noqa: F401
+
+
+def test_validating_introspection_query(benchmark, big_schema_sdl):  # noqa: F811
+    schema = build_schema(big_schema_sdl)
+    query = parse(introspection_query.get_introspection_query())
+    result = benchmark(lambda: validate(schema, query))
+    assert result == []