enhance: [GoSDK] Support return recall in search result (#39580)

Related to #37899

Signed-off-by: Congqi Xia <[email protected]>

client/milvusclient/read.go

@@ -71,6 +71,11 @@ func (c *Client) handleSearchResult(schema *entity.Schema, outputFields []string
 			sch:         schema,
 		}
 
+		// set recall if returned
+		if i < len(results.Recalls) {
+			entry.Recall = results.Recalls[i]
+		}
+
 		entry.IDs, entry.Err = column.IDColumns(schema, results.GetIds(), offset, offset+rc)
 		if entry.Err != nil {
 			offset += rc

client/milvusclient/results.go

@@ -37,6 +37,7 @@ type ResultSet struct {
 	IDs          column.Column // auto generated id, can be mapped to the columns from `Insert` API
 	Fields       DataSet       // output field data
 	Scores       []float32     // distance to the target vector
+	Recall       float32       // recall of the query vector's search result (estimated by zilliz cloud)
 	Err          error         // search error if any
 }