Remove and replace DoubledIsolated penalty by Doubled
The values for both penalties were very close, so DoubledIsolated can be removed and replaced by Doubled.
Passed STC (simplification): https://tests.stockfishchess.org/tests/view/5ec7c18e2a585b485af54407
LLR: 2.97 (-2.94,2.94) {-1.50,0.50}
Total: 105360 W: 20175 L: 20136 D: 65049
Ptnml(0-2): 1803, 12230, 24572, 12275, 1800
Passed LTC:
LLR: 2.94 (-2.94,2.94) {-1.50,0.50}
Total: 15440 W: 1978 L: 1877 D: 11585
Ptnml(0-2): 92, 1405, 4667, 1422, 134
closes https://github.com/official-stockfish/Stockfish/pull/2696
Bench: 4668875