fix(snowflake): Adding nonexistent tableExistsQuery to snowflake dialect query generator

[sfc-gh-dgadomski]

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• Have you added new tests to prevent regressions?
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Description Of Change

Starting from version 6.20.0 a new method tableExistsQuery is introduced and used by the sequelizesync method. Unfortunately this method is implemented in all dialects except snowflake. This causes snowflake dialect basically unusable. This PR fixes the issue by adding the implementation of tableExistsQuery in snowlake dialect.

[WikiRik]

Thanks for the PR! Unfortunately we do not have access to a snowflake instance to run integration tests so we are dependent on the community for that. We can run the unit tests of course so thanks for adding those here.

We'll review this soon

[WikiRik]

As mentioned before we cannot run integration tests but this change looks good to me. Can you make an additional PR to the v6 branch so we can land it there as well?

[github-actions]

🎉 This PR is included in version 7.0.0-alpha.17 🎉

The release is available on:

• npm package (@release-v7 dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[sfc-gh-dgadomski]

Thanks for merging it. I've just created another PR into v6 branch: #15087