Add per-minute records to the player Records page

[Xvie]

Adds Kills Per Min, Hero Damage Per Min and Tower Damage Per Min to the player Records page, so a long game no longer takes every damage record by default. In the screenshot the 22 minute Phantom Assassin game outranks a 62 minute Invoker game that has more than twice the absolute hero damage.

Depends on odota/core#2983 — those sort fields don't exist in the API yet, so the column stays blank until that ships.

Kept in a separate export from the default matchDataColumns list rather than added to it, since Histograms.tsx and Trends.tsx import the same default. The th_ strings already existed from the benchmarks work, so only the three heading_ button labels are new.

Ideally these would just go in the shared list and work everywhere, and Trends would in fact work as-is once odota/core#2983 lands, since it projects the field rather than hitting a whitelist. The blocker is histograms: bucketSize is Math.ceil((max + 1) / buckets), so the width can never drop below 1, and kills_per_min has a whole range under 1 — on a real 975 match account it puts 974 matches in bucket 0 and 1 in bucket 1. kda only escapes this because its range is large. Serving these from /histograms needs fractional bucket widths without changing how the existing integer fields bucket, which felt like its own change rather than something to bundle here. Happy to follow up with it, and the separate export goes away when that lands.

npm run build passes. I couldn't run npm test locally — testcafe/testsUtility.ts targets port 5000, which macOS AirPlay Receiver occupies on my machine.