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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)

...

""" Determine API and backend port based on Authorization headers. """
    target = headers.get('x-amz-target', '')
    host = headers.get('host', '')
    auth_header = headers.get('authorization', '')
    ls_target = headers.get(HEADER_LOCALSTACK_TARGET, '')
    path = path or '/'
    
    result = '_unknown_', 0
    
    try:
        credential_scope = auth_header.split(',')[0].split()[1]
        _, _, _, service, _ = credential_scope.split('/')
        result = service, get_service_port_for_account(service, headers)
    except Exception:
        pass
    result_before = result
    
    if host.endswith('cloudfront.net'):
        path = path or '/'
        result = 'cloudfront', config.PORT_CLOUDFRONT
    elif target.startswith('AWSCognitoIdentityProviderService') or 'cognito-idp.' in host:
        result = 'cognito-idp', config.PORT_COGNITO_IDP
    elif target.startswith('AWSCognitoIdentityService') or 'cognito-identity.' in host:
        result = 'cognito-identity', config.PORT_COGNITO_IDENTITY