Add SQL Server query notifications support

[arnabnandy7]

Description

Adds full SQL Server Query Notifications support, addressing #2910.

This introduces both low-level TDS subscription registration and a high-level Service Broker listener for Java applications that need event-driven cache invalidation or change detection without polling.

Changes

• Added SQLServerQueryNotificationRequest for configuring notification subscriptions.
• Added Query Notification TDS headers to SQL batch and RPC requests.
• Added statement APIs to set, retrieve, and clear notification requests.
• Added SQLServerQueryNotification as the notification event model.
• Added ISQLServerQueryNotificationListener for notification and error callbacks.
• Added SQLServerQueryNotificationListener with:
  • Dedicated Service Broker receive connection
  • Background daemon receiver
  • Configurable callback executor
  • Persistent callback registration
  • Automatic reconnection after connection failures
  • Service Broker conversation cleanup
  • Explicit queue and service creation/removal helpers
• Added secure notification XML parsing with DTD and external-entity protections.
• Added validation for request lengths, timeout ranges, payload structure, and listener arguments.
• Added usage and Service Broker setup documentation.
• Updated the changelog.

Usage

SQLServerQueryNotificationListener listener =
        new SQLServerQueryNotificationListener(dataSource, "ProductNotificationQueue");

listener.register("products-cache", notification -> {
    System.out.println(notification.getInfo());
    // Refresh data and re-execute the query to renew the one-time subscription.
});

listener.start();

SQLServerQueryNotificationRequest request =
        new SQLServerQueryNotificationRequest(
                "products-cache",
                "service=ProductNotificationService;local database=Products",
                300);

try (SQLServerPreparedStatement statement =
        (SQLServerPreparedStatement) connection.prepareStatement(
                "SELECT ProductID, Name FROM dbo.Products")) {
    statement.setQueryNotificationRequest(request);

    try (ResultSet resultSet = statement.executeQuery()) {
        // Populate the cache.
    }
}

Query Notification subscriptions remain one-shot, consistent with SQL Server behavior. Callback registrations remain active so applications can renew subscriptions using the same correlation key.

Validation

• JRE 8 compilation passed.
• JRE 11 compilation passed.
• 8 focused unit tests passed:
  • Request validation and protocol boundaries
  • Secure payload parsing
  • Malformed and unsafe XML rejection
  • Callback dispatch and persistent registration
  • Callback removal and listener validation
• git diff --check passed.

Testing limitation

Live Service Broker integration testing was not run locally because mssql_jdbc_test_connection_properties was not configured. The new functionality should be validated in CI against a Service Broker-enabled SQL Server instance.

Checklist

• Backward-compatible public API additions
• No new dependencies
• JRE 8 and JRE 11 compilation
• Unit tests added
• Public API Javadoc added
• Secure XML processing
• Service Broker lifecycle documented
• CHANGELOG updated

Closes #2910.