[SQL] INSERT INTO BUCKET FROM (subquery) silently fails

[gramian]

ArcadeDB Version 25.1.1

Inserting into a bucket via a sub-query reports inserted records but they don't exists, ie:

CREATE DOCUMENT TYPE src;
INSERT INTO src SET name = 'Hi';

CREATE DOCUMENT TYPE doc BUCKET doc;
INSERT INTO BUCKET:doc FROM (SELECT name FROM src); -- This fails silently

SELECT FROM BUCKET:doc; -- This returns 0 records

This (without BUCKET) works as expected:

CREATE DOCUMENT TYPE src;
INSERT INTO src SET name = 'Hi';

CREATE DOCUMENT TYPE doc BUCKET doc;
INSERT INTO doc FROM (SELECT name FROM src);

SELECT FROM doc; -- This returns 1 record

This reports: Error on command execution (PostCommandHandler): Cannot update a record in a custom bucket:

CREATE DOCUMENT TYPE doc BUCKET doc, src;
INSERT INTO BUCKET:src SET name = 'Hi';

INSERT INTO BUCKET:doc FROM (SELECT name FROM BUCKET:src);

[lvca]

In the InsertExecutionPlanner.handleInsertSelect() method, the CopyDocumentStep (which creates new documents from the SELECT results) was only added to the
execution plan when targetType was not null. When using INSERT INTO BUCKET:bucketName, the targetType was null and only targetBucket was set, causing the documents
from the SELECT to be passed through without being copied/created.

[lvca]

Solution:

1. Derive the target type from the bucket when targetType is null but targetBucket is specified
2. Use this derived type for the CopyDocumentStep, ensuring new documents are created

[gramian]

Works for me. Thank you!