A Mexican politician is sounding the alarm about a possible serial killer stalking women in the resort city of Puerto Vallarta — and possibly beyond. The body count has climbed to seven women murdered across the state of Jalisco and a chilling detail links at least two or possibly three of the cases: their blouses were nearly pulled off. Yussara Canales, a state legislator who represents Puerto Vallarta’s 5th district, told The Post on Thursday that evidence gathered by the Jalisco State