🔍 If there's a single legal move, make it immediately

[eduherminio]

a778a99: first impl, in NegaMax

8+0.08 aborted

Score of Lynx-single-legal-move-1457-win-x64 vs Lynx-for-loop-moves-1455-win-x64: 875 - 875 - 621  [0.500] 2371
...      Lynx-single-legal-move-1457-win-x64 playing White: 541 - 341 - 304  [0.584] 1186
...      Lynx-single-legal-move-1457-win-x64 playing Black: 334 - 534 - 317  [0.416] 1185
...      White vs Black: 1075 - 675 - 621  [0.584] 2371
Elo difference: 0.0 +/- 12.0, LOS: 50.0 %, DrawRatio: 26.2 %
SPRT: llr 0.333 (11.3%), lbound -2.94, ubound 2.94

40+0.4 aborted

   # PLAYER                           :  RATING  POINTS  PLAYED   (%)
   1 Lynx 1457 - single-legal-move    :  2200.9   499.0     993    50
   2 Lynx 1455 - for loop             :  2199.1   494.0     993    50

White advantage = 72.67
Draw rate (equal opponents) = 50.00 %

6+0.06 aborted

Score of Lynx 1457 - single-legal-move vs Lynx 1455 - for loop: 2520 - 2584 - 1998  [0.495] 7102
...      Lynx 1457 - single-legal-move playing White: 1544 - 1003 - 1003  [0.576] 3550
...      Lynx 1457 - single-legal-move playing Black: 976 - 1581 - 995  [0.415] 3552
...      White vs Black: 3125 - 1979 - 1998  [0.581] 7102
Elo difference: -3.1 +/- 6.8, LOS: 18.5 %, DrawRatio: 28.1 %
SPRT: llr -2.31 (-78.3%), lbound -2.94, ubound 2.94

5a47cfc: second impl, in IDFS:

8+0.08

Score of Lynx 1478 - single-legal-move vs Lynx 1475 - main: 2609 - 2515 - 2075  [0.507] 7199
...      Lynx 1478 - single-legal-move playing White: 1628 - 983 - 989  [0.590] 3600
...      Lynx 1478 - single-legal-move playing Black: 981 - 1532 - 1086  [0.423] 3599
...      White vs Black: 3160 - 1964 - 2075  [0.583] 7199
Elo difference: 4.5 +/- 6.8, LOS: 90.5 %, DrawRatio: 28.8 %
SPRT: llr 2.95 (100.1%), lbound -2.94, ubound 2.94 - H1 was accepted

A expected, more efficient achieving the same purpose since it doesn't interfere with regular searches and it avoids Aspiration Windows logic. Merging