Merge #669

669: Add ExhaustiveFacetCount parameter r=curquiza a=kashifsoofi

# Pull Request

## Related issue
Fixes #648 

## What does this PR do?
- ...

## PR checklist
Please check if your PR fulfills the following requirements:
- [x] Does this PR fix an existing issue, or have you listed the changes applied in the PR description (and why they are needed)?
- [x] Have you read the contributing guidelines?
- [x] Have you made sure that the title is accurate and descriptive of the changes?

Thank you so much for contributing to Meilisearch!


<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- New Features
  - Added support for an "exhaustive facet count" option in facet search queries, enabling users to request exhaustive counting of facet values.

- Documentation
  - Updated examples and samples to show how to enable the exhaustive facet count option in facet queries.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Co-authored-by: Kashif Soofi <kashif.soofi+git@gmail.com>

Author: meili-bors[bot]

.code-samples.meilisearch.yaml

@@ -834,6 +834,7 @@ facet_search_1: |-
 facet_search_3: |-
   var query = new SearchFacetsQuery()
   {
-    FacetQuery = "c"
+    FacetQuery = "c",
+    ExhaustiveFacetCount: true
   };
   await client.Index("books").FacetSearchAsync("genres", query);

src/Meilisearch/FacetSearchQuery.cs

@@ -43,5 +43,13 @@ public class FacetSearchQuery
         /// </summary>
         [JsonPropertyName("attributesToSearchOn")]
         public IEnumerable<string> AttributesToSearchOn { get; set; }
+
+        /// <summary>
+        /// When true, returns an exhaustive (exact) count for facet values during facet search.
+        /// This may increase response time on large datasets. Omit or set to false to favor performance.
+        /// Default (when null/omitted): server defaults apply.
+        /// </summary>
+        [JsonPropertyName("exhaustiveFacetCount")]
+        public bool? ExhaustiveFacetCount { get; set; }
     }
 }