Check all supported mime types the generator supports
Review Request #129610 - Created Dec. 4, 2016 and submitted
Stopping on the first inherit match can prevent finding a perfect match, and thus we might enter a competition of inherit matches from other generators. Example: spectre supports application/postscript and image/x-eps. When opening an eps the app/ps is an inherit match, but so is text/plain from the txt generator. Thanks to stable_sort() the txt generator is deterministically selected from the above two inherit matches. Unless we continue and find the perfect match, which is spectre:image/x-eps.