Summary

There are two group of tests in the repo: unit and integration. However some tests are missing the group definition in the @Test annotation. This causes these tests skipped. This PR fixes the problem:

• unit tests are all that have unit or no group
• integration tests are all that have integration group
• most test suite classes are marked as integration so all tests inside them will be executed at integration test stage despite specified group

Closes #2430

Checklist

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• Closes #
• Unit and integration tests covering the common scenarios were added
• A human-readable description of the changes was provided to include in CHANGELOG
• For significant changes, documentation in https://github.com/ClickHouse/clickhouse-docs was updated with further explanations or tutorials