seen search imdb_url should work similarly to how seen add imdb_url works #1427
Description
When running flexget seen add http://www.imdb.com/title/tt2660888/ it actually extracts the imdb_id and marks it as seen instead of the url. So if you later do flexget seen search http://www.imdb.com/title/tt2660888/ it will return no results. Seen search should behave the same way- if an imdb_url is passed, it should extract the imdb_id and do a lookup on it.