Extend the interface of `Gitlab::Ci::Reports::Security::Finding` with the `RAW_METADATA_ATTRIBUTES`

Why are we doing this work

In StoreReportService and FindingMap(for ingestion flow), we are parsing the raw_metadata attribute of the Gitlab::Ci::Reports::Security::Finding to access the following attributes to create Vulnerabilities::Finding records with;

• description
• message
• solution
• cve
• location

Ideally, we should parse the report artifact just once, therefore, we should make the description, message, and cve values as attributes of the Gitlab::Ci::Reports::Security::Finding.

The location and solution values should be populated by the related PORO value objects.

Non-functional requirements

• Documentation:
• Feature flag:
• Performance:
• Testing:

Implementation plan