feat: Add Dragonfly vector database cookbook with hybrid search examples

[vyavdoshenko]

Summary

This PR introduces a comprehensive Dragonfly vector database cookbook with practical examples of vector similarity search and hybrid queries using OpenAI embeddings, plus improvements to the Redis examples.

Motivation

This addition makes Dragonfly accessible to OpenAI Cookbook users and provides a practical alternative to Redis for vector database use cases, while also improving the Redis examples with proper dependency management.

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[github-actions]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[vyavdoshenko]

Nobody even looked at this PR. If maintainers don't want to receive changes, mention it in the README. If there's something wrong with this PR, please don't hesitate to point it out. If this PR is not desired to be merged, tell me here.

[github-actions]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[vyavdoshenko]

It seems my PR can be merged only if I am part of openai.

[github-actions]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[vyavdoshenko]

This PR is not stale. Nobody looks at this.

[github-actions]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 10 days.