There’s good news and bad news in the Boston Club’s latest survey on women in leadership positions at the 100 largest public companies in Massachusetts. The good news: The number of women chief executives in the state has doubled from last year. The bad news: That number is only six, up from three in 2010. Women’s progress in breaking through the glass ceiling remains frustratingly slow, according to the Boston Club, the women’s business group that conducts the annual survey.