Introduce a setting to hide embeddings

[curquiza]

Related product team resources: PRD (internal only)
Related product discussion: https://github.com/orgs/meilisearch/discussions/677

Motivation

Improve AI search performance

Usage

Introduce a setting to hide embeddings

https://meilisearch.notion.site/v1-9-AI-search-changes-e90d6803eca8417aa70a1ac5d0225697?pvs=74

TODO

Reminders when modifying the Setting API

• Ensure the new setting route is at least tested by the test_setting_routes macro
• Ensure Analytics are fully implemented
  • /settings/my-new-setting configurated in the make_setting_routes macro
  • global /settings route configurated in the update_all function
• Ensure the dump serializing is consistent with the /settings route serializing, e.g., enums case can be different (camelCase in route and PascalCase in the dump)

Special cases when adding a setting for an experimental feature

• ⚠️ API stability: The setting does not appear on the main settings route when the feature has never been enabled (e.g. mark it Unset when returned from the index in this situation. See an example)
• The setting cannot be set when the feature is disabled, either by the main settings route or the subroute (see validate_settings function)
• If possible, the setting is reset when the feature is disabled (hard if it requires reindexing)

Impacted teams

@meilisearch/docs-team @meilisearch/integration-team

[curquiza]

After discussing with the team, we finally choose to hide by default, so to implement only #4607

Of course, we will implement a setting if needed for users at some point.