Implemented S3 Account-level public access block.

- Also added AWS Config listing and fetching support
- Also fixed Lambda test breakage

moto/s3/exceptions.py

@@ -359,3 +359,12 @@ class InvalidPublicAccessBlockConfiguration(S3ClientError):
             *args,
             **kwargs
         )
+
+
+class WrongPublicAccessBlockAccountIdError(S3ClientError):
+    code = 403
+
+    def __init__(self):
+        super(WrongPublicAccessBlockAccountIdError, self).__init__(
+            "AccessDenied", "Access Denied"
+        )