After more than four years, a lawsuit over the conversion of a commercial space on Federal Street into housing has made its way to trial.  The lawsuit seeks to overturn a 2016 Salem Zoning Board of Appeals decision that allows Richard Jagolta to convert the first floor unit of 107 Federal St., which is zoned commercial, to a residential use. The suit was filed in August 2016 by attorney John Carr on behalf of residents of the Federal Street neighborhood.    Read the article………………………………