[Copilot]

Add a query() helper for sending HTTP QUERY requests with a body and request options.

• Convenience methods: Add query(), with async and mustQuery helper support.
• Async dispatch: Preserve uppercase HTTP method names for async requests.

$response = $client->query(
    'https://example.com/items',
    ['filter' => ['status' => 'active']],
    ['headers' => ['X-Request-Id' => 'abc']],
);

• Fixes HttpClient query() #1375