RPCN Browser: Migrate CommIDs from JSON to Compat DB

[FlexBy420]

Instead of using JSON for storing game title, ids and commids, use compat db instead.
Just a reminder issue for Ani to update RPCN page.

[AniLeo]

The data already exists in database and has been being populated for a few months

The missing things are adding a commID->gameID database, as well as a way to import data to it, and to rewrite the frontend to use the database instead