Add Ability To Analyze Files and Infer Metadata

[magneticstain]

Feature Summary

Plexer should analyze the files and directory structure of the target to infer the media's metadata.

Benefit

Currently, manually entering the metadata is tedious and time consuming. Having Plexer automatically do it will greatly improve the UX.

Additional context

Inference should be able to be performed using traditional programming. But machine learning methods may be used, if needed.

[magneticstain]

#40 should be a good stop-gap in improving the UX until we're able to implement this.