fix(completion): include PostgreSQL function parameters

crates/dbx-core/src/db/sqlserver.rs

@@ -1338,6 +1338,7 @@ pub async fn completion_assistant_search(
                 parent_name: row.get::<&str, _>(4).map(str::to_string),
                 comment: row.get::<&str, _>(5).filter(|s: &&str| !s.is_empty()).map(|s| (*s).to_string()),
                 data_type: row.get::<&str, _>(6).map(str::to_string),
+                signature: None,
             }
         })
         .collect::<Vec<_>>();