[cloud][aws] New module: cloudfront_invalidation (#35601)

* Remove redundant default for target_paths

* Make invalidation requests idempotent

* Remove redundant exception handling around boto3_conn

* Add cloudfront_invalidation to the changelog

lib/ansible/module_utils/aws/core.py

@@ -142,3 +142,6 @@ class AnsibleAWSModule(object):
         else:
             self._module.fail_json(msg=message, exception=last_traceback,
                                    **camel_dict_to_snake_dict(response))
+
+    def warn(self, msg):
+        self._module.warn(msg)