Add get movie info functionality

[tugcanolgun]

A way to download movie info again, with the choice of changing the movie's imdb id should be added.

back-end An api in panel/api should be added. It will recieve both the database movie object's id and an optional imdb id and repopulate the database instance.

front-end Update movie info option should be added to movie details page.

Eventually, redownload movie info (such as the redownload subtitles function) should be added to the settings. (out of the scope of this issue)