reorderQueue method
Implementation
void reorderQueue(int oldQueueIndex, int newQueueIndex) {
oldQueueIndex = oldQueueIndex + _index! + 1;
newQueueIndex = newQueueIndex + _index! + 1;
if (newQueueIndex > oldQueueIndex) newQueueIndex--;
var item = playlist.removeAt(oldQueueIndex);
playlist.insert(newQueueIndex, item);
}