CNDB-16395: Add SAI tests mixing static and non-static columns

[pkolaczk]

There is non-trivial amount of logic in SAI iterators code that
deal with PrimaryKey objects pointing to full partitions
and primary keys pointing to single rows. The tests added here
are a small step towards testing those code paths better.

[github-actions]

Checklist before you submit for review

• This PR adheres to the Definition of Done
• Make sure there is a PR in the CNDB project updating the Converged Cassandra version
• Use NoSpamLogger for log lines that may appear frequently in the logs
• Verify test results on Butler
• Test coverage for new/modified code is > 80%
• Proper code formatting
• Proper title for each commit staring with the project-issue number, like CNDB-1234
• Each commit has a meaningful description
• Each commit is not very long and contains related changes
• Renames, moves and reformatting are in distinct commits
• All new files should contain the DataStax copyright header instead of the Apache License one

[pkolaczk]

No need for a CNDB PR, this issue is pure testing.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[cassci-bot]

❌ Build ds-cassandra-pr-gate/PR-2276 rejected by Butler

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2 regressions found
See build details here

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Found 2 new test failures

Test	Explanation	Runs	Upstream
o.a.c.index.sai.cql.VectorCompaction100dTest.testZeroOrOneToManyCompaction[fa false]	REGRESSION	🔴⚪	0 / 27
o.a.c.index.sai.cql.VectorSiftSmallTest.testMultiSegmentBuild[ec true false]	NEW	🔴⚪	0 / 27

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Found 5 known test failures