Fix/1116 mixed cluster order for mv

[thmswt]

resolves dbt-labs/dbt-adapters#586
docs N/A

Problem

On creation of a materialized view the configured cluster_by order is not preserved.

Solution

Changing the type from FrozenSet to Tuple.

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

[github-actions]

This PR has been marked as Stale because it has been open with no activity as of late. If you would like the PR to remain open, please comment on the PR or else it will be closed in 7 days.