[X] bug report
[ ] feature request

# Detailed description

The AWS API supports Authorization parameters as GET parameters, e.g. here's a GET request to SendMessage on SQS:

```
curl 'http://localhost:4566/000000000000/SomeQueue.fifo?Action=SendMessage&MessageGroupId=Default&MessageDeduplicationId=1615597859837&MessageBody=%7B%22gateway_id%22%3A%20%2204e73c80-3539-499c-92a4-a0b106c2f6ab%22%7D&X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=test%2F20210313%2Fus-east-1%2Fsqs%2Faws4_request&X-Amz-Date=20210313T011059Z&X-Amz-Expires=86400000&X-Amz-SignedHeaders=host&X-Amz-Signature=2c652c7bc9a3b75579db3d987d1e6dd056f0ac776c1e1d4ec91e2ce84e5ad3ae'
```

## Expected behavior

Should send the message and return receipt information.

## Actual behavior

Returns...

```
<?xml version="1.0" encoding="UTF-8"?>
<Error>
    <Code>NoSuchBucket</Code>
    <Message>The specified bucket does not exist</Message>
    <BucketName>000000000000</BucketName>
    <RequestID>7a62c49f-347e-4fc4-9331-6e8eEXAMPLE</RequestID>
</Error>
```

body_key = 'MD5OfMessageBody' if outgoing else 'MD5OfBody'
            return set([
                (m[body_key], m['MD5OfMessageAttributes'])
                for m in messages
            ])
        messages_to_send = [
            {
                'Id': 'message{:02d}'.format(i),
                'MessageBody': 'msgBody{:02d}'.format(i),
                'MessageAttributes': {
                    'CustomAttribute': {
                        'DataType': 'String',
                        'StringValue': 'CustomAttributeValue{:02d}'.format(i)
                    }
                }
            }
            for i in range(1, 11)
        ]
        resp = self.client.send_message_batch(QueueUrl=queue_url, Entries=messages_to_send)
        sent_hashes = get_hashes(resp.get('Successful', []), outgoing=True)
        self.assertEqual(len(sent_hashes), len(messages_to_send))
        for i in range(2):
            messages = receive_messages(VisibilityTimeout=0)['Messages']
            received_hashes = get_hashes(messages)
            self.assertEqual(received_hashes, sent_hashes)
        self.client.delete_message_batch(
            QueueUrl=queue_url,
            Entries=[