VVLTC search tune

This set of parameters was derived from 3 tuning attempts:

    https://tests.stockfishchess.org/tests/view/65d19ab61d8e83c78bfd8436 (80+0.8 x8, ~40k games)
    Then tuned with one of linrock's early L1-3072 nets:
    https://tests.stockfishchess.org/tests/view/65def7b04b19edc854ebdec8 (VVLTC, ~36k games)
    Starting from the result of this tuning, the parameters were then tuned with the current master net:
    https://tests.stockfishchess.org/tests/view/65f11c420ec64f0526c46fc4 (VVLTC, ~45k games)

Additionally, at the start of the third tuning phase, 2 parameters were manually changed:

    Notably, the triple extension margin was decreased from 78 to 22. This idea was given by Vizvezdenec:
    https://tests.stockfishchess.org/tests/view/65f0a2360ec64f0526c46752.
    The PvNode extension margin was also adjusted from 50 to 40.

This tune also differs from previous tuning attempts by tuning the evaluation thresholds for smallnet and psqt-only.
The former was increased through the tuning, and this is hypothesized to scale better at VVLTC,
although there is not much evidence of it.

Passed VVLTC 1st sprt: https://tests.stockfishchess.org/tests/view/65f6761d0ec64f0526c4be88
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 44688 W: 11421 L: 11140 D: 22127
Ptnml(0-2): 1, 4170, 13722, 4449, 2

Passed VVLTC 2nd sprt: https://tests.stockfishchess.org/tests/view/65fa31a30ec64f0526c4f611
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 27450 W: 7057 L: 6778 D: 13615
Ptnml(0-2): 4, 2545, 8346, 2828, 2

STC Elo estimate: https://tests.stockfishchess.org/tests/view/65fd3e540ec64f0526c521ae
Elo: -7.84 ± 1.8 (95%) LOS: 0.0%
Total: 40000 W: 9899 L: 10802 D: 19299
Ptnml(0-2): 203, 5221, 10025, 4378, 173
nElo: -14.91 ± 3.4 (95%) PairsRatio: 0.84

closes https://github.com/official-stockfish/Stockfish/pull/5130

Bench: 1876107

src/evaluate.h

@@ -29,7 +29,7 @@ class Position;
 
 namespace Eval {
 
-constexpr inline int SmallNetThreshold = 1050, PsqtOnlyThreshold = 2500;
+constexpr inline int SmallNetThreshold = 1165, PsqtOnlyThreshold = 2500;
 
 // The default net name MUST follow the format nn-[SHA256 first 12 digits].nnue
 // for the build process (profile-build and fishtest) to work. Do not change the