⚡ Reimplement repetition detection

[eduherminio]

Reimplement repetition detection following the 'regular' method described in https://web.archive.org/web/20201107002606/https://marcelk.net/2013-04-06/paper/upcoming-rep-v2.pdf

[0, 3]

Score of Lynx-perf-new-repetition-detection-2693-win-x64 vs Lynx 2691 - main: 8746 - 8419 - 10562  [0.506] 27727
...      Lynx-perf-new-repetition-detection-2693-win-x64 playing White: 6063 - 2513 - 5289  [0.628] 13865
...      Lynx-perf-new-repetition-detection-2693-win-x64 playing Black: 2683 - 5906 - 5273  [0.384] 13862
...      White vs Black: 11969 - 5196 - 10562  [0.622] 27727
Elo difference: 4.1 +/- 3.2, LOS: 99.4 %, DrawRatio: 38.1 %
SPRT: llr 2.89 (100.0%), lbound -2.25, ubound 2.89 - H1 was accepted

There's a bench change, so something has changed, but elo is elo...