logging panel needs to use a stable sort
The logging panel sorts by timestamp, but this has the effect that lines with the same timestamp get sorted together in a way that messes up the original order.
This needs to
a) only sort by timestamp and not the rest of the line
b) use a stable sort (i.e. one that doesn't modify the original ordering for equivalent lines)
Because we're merging logs that are already in order, we don't need to sort at all, we just need to perform a merge that takes the next earliest line from each source.