Async HTTP/WebSocket Server Library for Teensy 4.1 using QNEthernet. This library is one of the Async libraries to support T4.1, such as AsyncHTTPRequest_Generic, AsyncHTTPSRequest_Generic, AsyncMQTT_Generic, AsyncWebServer_Teensy41, AsyncUDP_Teensy41, AsyncDNSServer_Teensy41, etc. Now supporting using CString to save heap to send very large data