Double extend search even more via LMR

Double extend search even more via LMR

Allow now for the first five moves a two plies deeper LMR search.

STC:
LLR: 2.96 (-2.94,2.94) <-2.50,0.50>
Total: 99608 W: 25143 L: 25115 D: 49350
Ptnml(0-2): 291, 11444, 26328, 11428, 313
https://tests.stockfishchess.org/tests/view/61718c9438cb9784038af8d7

LTC:
LLR: 2.95 (-2.94,2.94) <-2.50,0.50>
Total: 52064 W: 13234 L: 13145 D: 25685
Ptnml(0-2): 35, 5431, 15014, 5514, 38
https://tests.stockfishchess.org/tests/view/6171e13e38cb9784038af928

closes https://github.com/official-stockfish/Stockfish/pull/3760

Bench: 7222293