refactor feature database models #664
Description
After thinking about it for a while, features should exist in two tables: one which stores metadata about each individual feature, and the other which maps discord IDs to whether or not a feature is enabled.
An IDs to feature table where feature names are the columns and the ID override is a true/false/null for each column
Futher thought is required on whether or not getting the guild features with the config makes any sense.