Add clipboard logs

Synchronizing local and device clipboards in invisible. Add INFO logs
on success.

app/src/receiver.c

@@ -26,6 +26,7 @@ static void
 process_msg(struct receiver *receiver, struct device_msg *msg) {
     switch (msg->type) {
         case DEVICE_MSG_TYPE_CLIPBOARD:
+            LOGI("Device clipboard copied");
             SDL_SetClipboardText(msg->clipboard.text);
             break;
     }

server/src/main/java/com/genymobile/scrcpy/Device.java

@@ -149,6 +149,7 @@ public final class Device {
 
     public void setClipboardText(String text) {
         serviceManager.getClipboardManager().setText(text);
+        Ln.i("Device clipboard set");
     }
 
     static Rect flipRect(Rect crop) {