[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>
```

ident = self._ident()
        removed = self.CONTEXTS_BY_THREAD.pop(ident, None)
        if not self.CONTEXTS_BY_THREAD:
            
            self._set(self.orig_stdout, self.orig_stderr, self.orig___stdout, self.orig___stderr)
        
        removed._stdout.flush()
        removed._stderr.flush()
        out = removed._stdout.getvalue()
        err = removed._stderr.getvalue()
        
        removed._stdout.close()
        removed._stderr.close()
        removed._stdout = out
        removed._stderr = err
    def _set(self, out, err, __out, __err):
        sys.stdout, sys.stderr, sys.__stdout__, sys.__stderr__ = (out, err, __out, __err)
    def _proxy(self, original_stream, type):
        def proxy():
            ident = self._ident()
            ctx = self.CONTEXTS_BY_THREAD.get(ident)
            if ctx:
                return ctx._stdout if type == 'stdout' else ctx._stderr
            return original_stream
        return proxy
    def _ident(self):
        return threading.currentThread().ident
    def stdout(self):