Add statistics about queue length

[marcoabreu]

Add statistics to the website that show data about the queue length per map.

There are various ways to approach this:

There could be a upper, lower percentile, median and average per timeframe (e.g. hour).
There could be a simple bar-char that displays how many people have been in the queue for < 1 min, 1-2 min, 2-3 min before they joined a game. But also stats about how much time passed before somebody aborted the search.

Goal is to allow users as well as developer to see how the queue behaves during different times of day and to determine break-even points of queue durations.

[Cepheid-UK]

We do collect data manually on queue lengths, so this would be great to have in the admin panel, if anyone wants to discuss how this should work, those with data-science role on discord should be able to give some advice. It will for sure require some backend work too though, and I can help a little with that, or modmoto/abeninski