Improve the pipeline of potential games

[paul-roman]

Every time a potential game is found, a new request is done on IGDB API to get the game name and cover picture. This system is really expensive in both terms of IGDB API requests number (since they are capped) and performance (each request lasts multiple ms).
Plus, everytime a potential game is added, the rest of the potential games are once again found on the computer and sent to IGDB API, which can lead to 100+ requests in 10 seconds.

A solution to solve that would be to "cache" the potential games using a file.