Patch moto to be able to test the S3 ListParts API

For several reasons, we should patch upstream moto, the module we are using to test S3 uploads:

• we cannot test S3 uploads completely because there is no available server with S3 enabled on our CI;
• so we try to test S3 critical parts only (but correctly).

And so, we _need_ to be able to test every API we are using. In that case, the ListParts API is used to retrieved already sent parts of a given multipart upload ID. As this API returns parts by batch, we need to call it several times to retrieve all uploaded parts.

And this is currently not testable because of a lack of implementation in moto.

I already opened an issue on their repository.