Split timings into tree reports
this will allow the timings site to display timings as a tree, instead of as a list as is done now, which will enable more precise identification of performance issues.
An example of this can be seen here: https://timings.pmmp.io/?id=302629
The format changes are fully backwards compatible, as the timings site
aggregates timings from timers with the same names, and doesn't limit
how much extra data can appear at the end of a line.
this gives a somewhat better overview of events, particularly if many plugins are subscribed to the same costly event (e.g. PlayerMoveEvent).
In addition, it allows us to see the frequency that events are occurring.
since item merging is a potential hotspot, we want to know if this code section is a performance problem.
Current timers only tell us whether overall ticking of a particular entity is slow, but that includes movement and therefore isn't particularly helpful.
this has been a bug ever since Snooze was first introduced. The load statistic, similarly to timings, did not account for time spent processing notifications between ticks. The problem is that this is often where a significant amoutn of the load actually comes from, because Snooze is most often activated due to incoming packets.
This change fixes the problem by including the time spent processing notifications since the previous tick in the current tick's usage metric.
this avoids duplicate timings entries when command labels are changed and changed back, or if multiple command maps are in use.
In addition, it also solves some PHPStan issues :)
this fixes#3906.
TimingsHandler will now be automatically destroyed when there are no TimingsRecord referencing it and its owner has no references left to it.
TimingsRecord will be automatically destroyed at the end of the timings session (if active).
This fixes records from temporary timers being lost after the timings handlers are removed, while also fixing TimingsHandlers piling up regardless of whether timings are running or not.
This opens the doors to have more volatile timers, such as per-player/per-session timers, which are destroyed on player quit, but which won't result in the timings disappearing from the final timings result.
