CNDB-15469: Implement NVQ for vector graphs built by compaction

[michaeljmarshall]

What is the issue

Fixes: https://github.com/riptano/cndb/issues/15469

What does this PR fix and why was it fixed

This is a draft and is not yet complete.

The main open questions come from how to store vectors in an addressable way so that we can iterate them and write them to the correct location. Saving this as a draft to prevent the work from getting lost.

[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