Fix msb definition affecting eval reflectivity due to king shelter calculations

[TheRealGioviok]

Also fix unused PieceId msb definition and added eval reflectivity test script.

Passed nonregr STC:

Test  | fixreflective
Elo   | 4.57 +- 3.57 (95%)
SPRT  | 8.0+0.08s Threads=1 Hash=16MB
LLR   | 2.96 (-2.94, 2.94) [-3.00, 0.00]
Games | N: 13084 W: 3511 L: 3339 D: 6234
Penta | [179, 1540, 2947, 1682, 194]

https://ob.cwchess.org/test/1408/

Bench: 14793132