5223: Limit batched tasks total size r=curquiza a=Kerollmops
Introduce a new engine parameter (env and config, too) to limit the maximum payload size processed by the engine in batches. You can [review the Discussion and usage on GitHub](https://github.com/orgs/meilisearch/discussions/801).
Co-authored-by: Clément Renault <clement@meilisearch.com>