Update row filter expression formatting in Trino authorization

- Modified the row filter expression construction to wrap each expression in parentheses for improved clarity and consistency.
- This change enhances the readability of the generated query strings used in authorization checks.

This commit refines the handling of row filter expressions, contributing to better structured queries in the PDP server's Trino integration.

Author: danyi1212

pdp-server/src/api/trino/row_filter.rs

@@ -152,7 +152,7 @@ async fn get_row_filter_expressions(
         query.context.identity.user,
         expressions
             .iter()
-            .map(|e| e.expression.clone())
+            .map(|e| format!("({})", e.expression.clone()))
             .collect::<Vec<String>>()
             .join(" AND ")
     );