Congregants at the Forest Hills Jewish Center, a fixture in Queens since the late 1940s, approved the sale Thursday evening of their block-long building. They will now begin the process of finding a new home in the same area. “The vote was overwhelmingly for the sale,” said Carl Koerner, chair of the building committee. The 400-family unit Conservative congregation’s synagogue at 106-06 Queens Boulevard has been on the market for about a year. The asking price was $50 million, but Koerner said the terms of the sale to a developer would not be made public until it is approved by...