HogQL: Support for CTEs in a union query

[thmsobrmlr]

Is your feature request related to a problem?

A CTE is only accessible from the first query in a union query.

WITH test AS (SELECT 123 AS value)
SELECT value FROM test
UNION ALL
SELECT value FROM test

Describe the solution you'd like

CTEs should be handled in the same way ClickHouse does.

Describe alternatives you've considered

Repeating the CTE for each query.