Add ability to tag scanned content

[makstermaki]

Currently, when a TV show is added to the database, only the show name is passed in along side it. To then add that show to a channel, the specific show needs to be passed to the channel. This means for a channel to have 10 shows, all 10 shows would have to be passed to the channel. Instead of having to pass every single show to be played on a channel manually, a tagging system should be implemented for the scanned content. When a show is then added to be scanned, not only will the name of the show be passed, a list of tags may also be passed. Then on channel creation, a set of tags can be passed in and all shows with those tags would be used to generate the channel.