Add support for X-SS-Connect-Data in RTSP SETUP for control stream

This allows the host to provide a 32-bit integer that will be sent
in the data of the ENet connect event, similar to X-SS-Ping-Payload
for video and audio.

The host can use this data to uniquely identify a client when IP
addresses are not stable across the various separate connections,
such as when the client is behind a Carrier-Grade NAT.

src/SdpGenerator.c

@@ -268,7 +268,7 @@ static PSDP_OPTION getAttributesList(char*urlSafeAddr) {
 
     // Send client feature flags to Sunshine hosts
     if (IS_SUNSHINE()) {
-        uint32_t moonlightFeatureFlags = ML_FF_FEC_STATUS;
+        uint32_t moonlightFeatureFlags = ML_FF_FEC_STATUS | ML_FF_SESSION_ID_V1;
         snprintf(payloadStr, sizeof(payloadStr), "%u", moonlightFeatureFlags);
         err |= addAttributeString(&optionHead, "x-ml-general.featureFlags", payloadStr);
     }