Merge #5371

5371: Composite embedders r=irevoire a=dureuill

# Pull Request

## Related issue
Fixes #5343 

## What does this PR do?
- Implement [public usage](https://www.notion.so/meilisearch/Composite-embedder-usage-14a4b06b651f81859dc3df21e8cd02a0)
- Refactor the way we check if a parameter is mandatory/allowed/disallowed for a given source
- Take the "nesting context" into account for computer if a parameter is mandatory/allowed/disallowed
- Add tests checking all parameters with all sources, and made sure the results didn't change compared with v1.13

## Dumpless Upgrade

- This adds a new value for an existing parameter => compatible without change
- This adds new optional parameters => compatible without change

Co-authored-by: Louis Dureuil <louis@meilisearch.com>

crates/milli/src/search/hybrid.rs

@@ -203,7 +203,7 @@ impl<'a> Search<'a> {
 
                 let deadline = std::time::Instant::now() + std::time::Duration::from_secs(3);
 
-                match embedder.embed_one(query, Some(deadline)) {
+                match embedder.embed_search(query, Some(deadline)) {
                     Ok(embedding) => embedding,
                     Err(error) => {
                         tracing::error!(error=%error, "Embedding failed");