[ADD] Performance test for onlylegalmoves method
[ADD] Performance test for onlylegalmoves method

Note: I found the bottleneck. It is somewhere in this method. The
execution of this method is more then 1000% of the other methods in
generatemovelist combined.

kmiller96/Quark-ChessEngine,kmiller96/Quark-ChessEngine,kmiller96/QuantumChessEngine