Tweak static eval history update

Modify the applied static eval bonus for main and pawn history with different
factors for positive and negative values.

Passed STC:
https://tests.stockfishchess.org/tests/view/659132e179aa8af82b957bb0
LLR: 2.93 (-2.94,2.94) <0.00,2.00>
Total: 12512 W: 3308 L: 3027 D: 6177
Ptnml(0-2): 32, 1372, 3189, 1609, 54

Passed LTC:
https://tests.stockfishchess.org/tests/view/65913e3d79aa8af82b957cd2
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 35946 W: 9128 L: 8809 D: 18009
Ptnml(0-2): 19, 3879, 9862, 4190, 23

closes #4952

Bench: 1392883

src/search.cpp

@@ -772,6 +772,7 @@ Value search(Position& pos, Stack* ss, Value alpha, Value beta, Depth depth, boo
     if (is_ok((ss - 1)->currentMove) && !(ss - 1)->inCheck && !priorCapture)
     {
         int bonus = std::clamp(-13 * int((ss - 1)->staticEval + ss->staticEval), -1652, 1546);
+        bonus     = bonus > 0 ? 2 * bonus : bonus / 2;
         thisThread->mainHistory[~us][from_to((ss - 1)->currentMove)] << bonus;
         if (type_of(pos.piece_on(prevSq)) != PAWN && type_of((ss - 1)->currentMove) != PROMOTION)
             thisThread->pawnHistory[pawn_structure_index(pos)][pos.piece_on(prevSq)][prevSq]