feat: add the explain_plan function (#1328)

It's useful to see the underlying query plan for debugging purposes.
This exposes LanceScanner's `explain_plan` function. Addresses #1288

---------

Co-authored-by: Will Jones <willjones127@gmail.com>

nodejs/src/query.rs

@@ -80,6 +80,13 @@ impl Query {
             })?;
         Ok(RecordBatchIterator::new(inner_stream))
     }
+
+    #[napi]
+    pub async fn explain_plan(&self, verbose: bool) -> napi::Result<String> {
+        self.inner.explain_plan(verbose).await.map_err(|e| {
+            napi::Error::from_reason(format!("Failed to retrieve the query plan: {}", e))
+        })
+    }
 }
 
 #[napi]
@@ -154,4 +161,11 @@ impl VectorQuery {
             })?;
         Ok(RecordBatchIterator::new(inner_stream))
     }
+
+    #[napi]
+    pub async fn explain_plan(&self, verbose: bool) -> napi::Result<String> {
+        self.inner.explain_plan(verbose).await.map_err(|e| {
+            napi::Error::from_reason(format!("Failed to retrieve the query plan: {}", e))
+        })
+    }
 }