Provide CLI tool for showing information from torrent file

Basically, provide a tool similar to transmission-show, but add support for structured output and accessing all information, including the source tag. This tool will be part of how to use gamayun. For example, to seed torrents from directories based on the tracker, one could do something like gamayun --add foo.torrent --dir /seed/$(gamayun-info --source foo.torrent)