Keep StopWatch.formatSplitTime from clamping splits to int millis

[alhudz]

StopWatch.formatSplitTime() feeds the split Duration through DurationUtils.toMillisInt, which clamps the millisecond value into int range. A split longer than Integer.MAX_VALUE ms (about 24.86 days) is capped, so formatDurationHMS renders the cap rather than the real elapsed time. Backdating the start by 30 days and calling split() gives formatSplitTime() = 596:31:23.647 while getSplitDuration() is PT720H (720:00:00.008).

formatDurationHMS already takes a long, and the sibling formatTime() hands it getTime() with no narrowing, so route the split path through DurationUtils.toMillisLong instead. Keeping the value a long up to the formatter is what drops the truncation, and normal-length splits are unchanged.