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# Type of request: This is a ...

[x] bug report
[ ] feature request

# Detailed description

In the `ReceiveMessageResult` of the SQS service, I saw this XML from localstack:

```
...
<MessageAttribute>
     <Name>encoding</Name>
    <Value>
        <DataType>String</DataType>
        <StringValue><![CDATA[gzip]]></StringValue>
    </Value>
</MessageAttribute>
...
```

The `<![CDATA[gzip]]>` is slightly different from AWS, which doesn't wrap the value in a `<!CDATA[[]]>` section. This shouldn't be a problem for XML parsers that accept both plain characters and CDATA sections for this element, but the XML parser I was using did not, which causes an error when running the code against localstack but not when running the code against AWS. There is obviously a bug in the XML parser as well, but I thought that I should at least post this here since it is different than what AWS SQS does.

## Expected behavior

MessageAttribute::Value elements should not be wrapped in `CDATA` sections.

## Actual behavior

MessageAttribute::Value elements all seem to be wrapped in `CDATA` sections.

# Steps to reproduce

Send a message to the SQS service which contains some custom message attributes, then make a ReceiveMessageRequest.

## Command used to start LocalStack

`docker run --env "SERVICES=sqs" localstack/localstack`

## Client code (AWS SDK code snippet, or sequence of "awslocal" commands)

...

for thread in TMP_THREADS:
        if thread:
            try:
                if hasattr(thread, 'shutdown'):
                    thread.shutdown()
                    continue
                thread.stop(quiet=quiet)
            except Exception as e:
                print(e)
    for p in TMP_PROCESSES:
        try:
            p.terminate()
        except Exception as e:
            print(e)
    
    try:
        import asyncio
        for task in asyncio.all_tasks():
            try:
                task.cancel()
            except Exception:
                pass
    except Exception:
        pass
    
    clear_list(TMP_THREADS)
    clear_list(TMP_PROCESSES)
def clear_list(list_obj):