Add --multipv flag to run analyzer in multipv 2

[fsmosca]

Get scores and pv lines from multipv 2 search, and also add 2nd bestmove and bestscore in the move comment during analysis if its score is not too far from the score of the game move. This would allow the user to see more possibilities in the game.

[shapiro85]

Hi Ferdinand,
I hope you are doing very well.
Could you please Add --multipv flag to run analyzer in multipv 2

[taniaMashenko]

Hi Fredy,
God Bless your family
Could you kindly Add --multipv flag to run analyzer in multipv 2