Feature summary (what you would like to be able to do and where): Allow users input api key for third party LLM service provider, and use them to provide automatic translation in Content Translation

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
Currently, auto translation in Content Translation have been disabled for languages like Chinese and Japanese, due to low accuracy and possibility of hallucinations when using existing translation engines based on NMT or even Statistical Machine Translation.
A more accurate translation tool with accuracy that community can accept, will be able to allow users of Wikipedia of these language editions to enjoy the benefits of auto translation in Content Translation tool. (Which I think require GPT 4o/Claude 3.5 Sonnet level of models to provide good enough performance thus might be a bit difficult for most open source models out there nowadays, therefore suggesting the use of third party LLM service provider via user API key, instead of deploying/using open source LLM)

Benefits (why should this be implemented?):
All major Wikipedia language editions that currently disabled auto translation in Content Translation tool, through such implementation, can finally benefits from auto translation without disadvantage from before.

Smaller languages that have been poorly supported by machine translation tools until now, can also benefits from using LLM for auto translation.

The use of auto translation of to transfer Wikipedia article materials across language editions can also help reduce POV bias between different language editions