WebDriver: Implement stub for /session/{id}/print

Author: https://github.com/Baitinq
Commit: 02a2018ec4
Pull-request: https://github.com/SerenityOS/serenity/pull/16216
Reviewed-by: https://github.com/linusg

Userland/Services/WebContent/WebDriverClient.ipc

@@ -53,4 +53,5 @@ endpoint WebDriverClient {
     send_alert_text(JsonValue payload) => (Web::WebDriver::Response response)
     take_screenshot() => (Web::WebDriver::Response response)
     take_element_screenshot(String element_id) => (Web::WebDriver::Response response)
+    print_page() => (Web::WebDriver::Response response)
 }