Import Ubuntu OSV data

[pombredanne]

See:

• https://github.com/canonical/ubuntu-security-notices/
  There is a pending license issue to resolve:
• Clarify data license for these notices canonical/ubuntu-security-notices#5

[kunalsz]

@pombredanne isn't this license here https://github.com/canonical/ubuntu-security-notices/blob/main/LICENSE enough to allow us to use the advisory data ? But GPL licensing is done for software not data, using GPL might require us to refactor VulnerableCode's license also as GPL.

[pombredanne]

@kunalsz per canonical/ubuntu-security-notices#5 (comment)

@pombredanne we already discussed this with @oliverchang and legal, and GPL doesn't apply to data, but only to the scripts in this repo.

regarding clarifying it, I will discuss with the rest of the team about it, we will update this PR when done

In all cases, the license should not be in the way to writing the code to fetch the data unless the license would prohibit that, which is not the case.

[pombredanne]

Note also that https://github.com/canonical/ubuntu-security-notices/ now has three formats, and include PURLs in most cases! ( @dodys thank you for that! ❤ )