Migrate from Postgres to SQLite

[corndogit]

Postgres is too heavy-duty for the use case of just having a database of songs to query. Look at moving to SQLite as a more lightweight data store

Changes should work with existing database CRUD functions and dockerfiles + compose files should be updated too

[corndogit]

Need to have a long think of the pros and cons before doing this

Pros: lower resource usage on server (CPU, RAM and storage)

Cons: limits future possible work, slightly unfamiliar