Respect insert_allow_materialized_columns for INSERT into Distributed table

Why it matters

This feature addresses the limitation where inserting data into Distributed tables did not honor the insert_allow_materialized_columns setting, preventing insertion into materialized columns. It allows users to insert data that includes materialized columns through distributed tables, improving data insertion flexibility and consistency.

How to use it

To use this feature, set the insert_allow_materialized_columns setting to true when inserting into a Distributed table. For example, use the following setting in your client or query:

SET insert_allow_materialized_columns = 1;
INSERT INTO distributed_table VALUES (...);