Use less time on recaptures

Credit for the idea goes to peregrine on discord.

Passed STC 10+0.1:
https://tests.stockfishchess.org/tests/view/662652623fe04ce4cefc48cf
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 75712 W: 19793 L: 19423 D: 36496
Ptnml(0-2): 258, 8487, 20023, 8803, 285

Passed LTC 60+0.6:
https://tests.stockfishchess.org/tests/view/6627495e3fe04ce4cefc59b6
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 49788 W: 12743 L: 12404 D: 24641
Ptnml(0-2): 29, 5141, 14215, 5480, 29

The code was updated slightly and tested for non-regression against the
original code at STC:

LLR: 2.94 (-2.94,2.94) <-1.75,0.25>
Total: 41952 W: 10912 L: 10698 D: 20342
Ptnml(0-2): 133, 4825, 10835, 5061, 122
https://tests.stockfishchess.org/tests/view/662d84f56115ff6764c7e438

closes https://github.com/official-stockfish/Stockfish/pull/5189

Bench: 1836777

src/search.h

@@ -109,8 +109,7 @@ struct RootMove {
 using RootMoves = std::vector<RootMove>;
 
 
-// LimitsType struct stores information sent by GUI about available time to
-// search the current move, maximum depth/time, or if we are in analysis mode.
+// LimitsType struct stores information sent by the caller about the analysis required.
 struct LimitsType {
 
     // Init explicitly due to broken value-initialization of non POD in MSVC
@@ -128,6 +127,7 @@ struct LimitsType {
     int                      movestogo, depth, mate, perft, infinite;
     uint64_t                 nodes;
     bool                     ponderMode;
+    Square                   capSq;
 };