Add creation logic for vulnerability read ingestion

What does this MR do and why?

Adds in logic for the creation of vulnerability reads to be at the application level instead of doing it with raw SQL. This allows the process to be more transparent and therefore debuggable, which helps when dealing with data consistency issues. It also introduces a feature flag to manage the current logic and this new logic that will eventually replace it. Closes #541893 (closed). Closes #546223 (closed).

References

• &12380

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