Deduplicated package license support

What does this MR do and why?

In order to reduce the package metadata dataset size, a deduplication strategy has to be used to compress license data into a licenses jsonb column.

This MR

• adds the licenses column
• updates the PackageMetadata::Package model validation for the added column
  • to have the most compact json in the database, licenses uses a 3-element array rather than a json object (implementation outline: #408901 (closed))

Screenshots or screen recordings

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How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #408757 (closed)