[Feature] Manually add games to libraries

[gsabater]

What is about

A feature to let users add games to their libraries.

This could be a real game that can be searched and referenced (even if is not yet in the backlog.rip database) or a manually created game only for the user.

Challenges

• Interface to search games in other sources, and reference it.
• Adding the game to the backlog.rip database for everyone, and get metadata and media
• Adding the game immediately to the user library for categorization

Mentions

• Suggested by Moortu via Discord