Allow db_engine = 'Shared' in supports_atomic_exchange()

[herbert-allium]

Summary

Allow db_engine = 'Shared' for atomic exchange, in addition to the Atomic and Replicated database engines.

The Clickhouse docs on the EXCHANGE statement mentions support for db_engine = 'Shared':

Checklist

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• A human-readable description of the changes was provided to include in CHANGELOG

[windsurf-bot]

Looks good to me 🤙

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[koletzilla]

Hi @herbert-allium ! Thanks for your contribution.

I thought this was already fixed by #498, but I see that also your change looks needed.

I'd like to take a deep look at this to understand why we have this duplicated check. Feel free to also make the needed changes so we don't have to keep two different lists of "databases that can use exchange"

[herbert-allium]

@koletzilla I created engine_can_atomic_exchange in dbt/adapters/clickhouse/util. I'm unsure if this is the correct folder, I can also move it to somewhere else if you prefer.

[herbert-allium]

Hi @koletzilla, how is this?