Add ratings

[parsiad]

Allows a user to get metacritic ratings using a RAWG API key and sort by them.

See #2623 and #3800.

Currently the API is hit with a single process and hence hydrating a large library can take a while. A future PR can add multiple workers and 429 backoff so as to not overwhelm the endpoint.

Disclaimer: AI assisted.

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Use the following Checklist if you have changed something on the Backend or Frontend:

• Tested the feature and it's working on a current and clean install.
• Tested the main App features and they are still working on a current and clean install. (Login, Install, Play, Uninstall, Move games, etc.)
• Created / Updated Tests (If necessary)
• Created / Updated documentation (If necessary)

[flavioislima]

All contributors have signed the CLA ✍️ ✅
_{Posted by the CLA Assistant Lite bot.}

[parsiad]

I have read the CLA Document and I hereby sign the CLA