[FEATURE] Sample implementation of PLI callback

[hassanctech]

The SDK provides this public API

/**
 * @brief Set a callback for picture loss packet (PLI)
 *
 * @param[in] PRtcRtpTransceiver Populated RtcRtpTransceiver struct
 * @param[in] UINT64 User customData that will be passed along when RtcOnPictureLoss is called
 * @param[in] RtcOnPictureLoss User RtcOnPictureLoss callback
 *
 * @return STATUS code of the execution. STATUS_SUCCESS on success
 */
PUBLIC_API STATUS transceiverOnPictureLoss(PRtcRtpTransceiver, UINT64, RtcOnPictureLoss);

But there is no sample implementation for the user callback that might be beneficial to maintain stream integrity.

If anyone has experience implementing this please share your ideas or feel free to contribute a sample!