Draft: BLS trigger: Beex Alg (ATR-22749)

@lyubushk @tursom @hrussell @jakoubek

I have ported the old Beex algorithm using the logic Vladimir established in the BmumuX code.

I have removed the 2 track vertexing as this seems useless?

Can you check and make any comments on the logic or cuts. We still need to set up the chain and I've asked the egamma people for some help.