Function query_response_xml 

pub fn query_response_xml(
    action: &str,
    namespace: &str,
    inner: &str,
    request_id: &str,
) -> String

Wrap an action result in the standard AWS Query protocol XML envelope.

Produces the canonical response shape:

<?xml version="1.0" encoding="UTF-8"?>
<{Action}Response xmlns="{namespace}">
  <{Action}Result>{inner}</{Action}Result>
  <ResponseMetadata><RequestId>{request_id}</RequestId></ResponseMetadata>
</{Action}Response>