Adds a feed_channel implementation which reflects a feed's specific
settings per channel.
Also added an UnparsedTimedScore to score which allows parsing to score
from db in a controlled fashion.
Creates a fetch mod for fetching remote rss content.
This implementation is barebones and not great since it doesn't pass any
compression or timestamp information.
Adds SQLX for database management, and an Adapter interface for
interacting with it. Through the type "AdapterPool"
Creates an initial_schema with everything I think I'll need.