Support for storing vulndb data in mysql/postgresql

[kakumanivrn]

As of now vulndb data is being used by dep-scan but it's storing the data on storage volume which is not ideal for it's size. Especially in production environment. So I think it would be great to store vulnerabilities data in database.

[prabhu]

@kakumanivrn, the dual file format is optimized for performance, and dep-scan is generally faster than equivalent products such as dependency-check that could use a database. However, I was able to knock out a version that used Google firestore as the backend for one of the projects, so would add this script to a contrib folder when I get a chance.