Improve quiet moves bonus
Inspired by an old test by Peregrine.
Passed STC:
LLR: 2.94 (-2.94,2.94) <0.00,2.00>
Total: 453024 W: 117244 L: 116316 D: 219464
Ptnml(0-2): 1336, 53355, 116258, 54171, 1392
https://tests.stockfishchess.org/tests/view/680ccacc3629b02d74b15532
Passed LTC:
LLR: 2.94 (-2.94,2.94) <0.50,2.50>
Total: 140550 W: 35990 L: 35462 D: 69098
Ptnml(0-2): 65, 15152, 39319, 15668, 71
https://tests.stockfishchess.org/tests/view/680d2ed73629b02d74b15691
closes https://github.com/official-stockfish/Stockfish/pull/6028
Bench: 1708152