Optimise MovePicker

[kelseyde]

Stopping early as this is speedup elo:

Score of Calvin DEV vs Calvin: 190 - 180 - 638  [0.505] 1008
...      Calvin DEV playing White: 152 - 42 - 309  [0.609] 503
...      Calvin DEV playing Black: 38 - 138 - 329  [0.401] 505
...      White vs Black: 290 - 80 - 638  [0.604] 1008
Elo difference: 3.4 +/- 13.0, LOS: 69.8 %, DrawRatio: 63.3 %

After a bit more tweaking to movegen:

Score of Calvin DEV vs Calvin: 392 - 379 - 1062  [0.504] 1833
...      Calvin DEV playing White: 326 - 75 - 516  [0.637] 917
...      Calvin DEV playing Black: 66 - 304 - 546  [0.370] 916
...      White vs Black: 630 - 141 - 1062  [0.633] 1833
Elo difference: 2.5 +/- 10.3, LOS: 68.0 %, DrawRatio: 57.9 %

Combined:
+3 +/- 8, good enough for me given it's just speedup elo.