VVLTC parameters tweak

Some notes:
- Both tests were conducted on top of official-stockfish#5848.
- Based on tuning suggestions, the extension for capturing the
  previously moved piece was removed/simplified. (Developers can attempt
  to reintroduce it post-merge if needed.)
- Initially, bonusScale = std::max(bonusScale, -2); was included but
  later removed in the second test upon Viz's request, however, it was
  nearly non-functional anyway.

Passed VVLTC under STC bounds:
LLR: 2.95 (-2.94,2.94) <0.00,2.00>
Total: 31508 W: 8153 L: 7895 D: 15460
Ptnml(0-2): 1, 2747, 10005, 2995, 6
https://tests.stockfishchess.org/tests/view/679fdc7a0774dfd78deb1350

Passed VVLTC under LTC bounds:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 55026 W: 14370 L: 14046 D: 26610
Ptnml(0-2): 7, 4957, 17262, 5279, 8
https://tests.stockfishchess.org/tests/view/679fec920774dfd78deb19b8

closes official-stockfish#5856

Bench: 2757788