Remove usage of `message` field in Vulnerabilities

Why are we doing this work?

With Deprecate and stop processing `message` field i... (#411573 - closed) we will have stopped processing the message attribute from both CI pipelines and GraphQL mutations. In order to prepare for dropping the column we should ignore the message column and make necessary adjustments

Implementation plan

1. Mark the message column as ignored according to database guidelines
2. Make necessary adjustments in the code base, a non-exhaustive list of places:

• ee/app/services/vulnerabilities/create_service_base.rb
• ee/app/services/vulnerabilities/manually_create_service.rb
• ee/app/services/vulnerabilities/starboard_vulnerability_create_service.rb
• ee/app/services/vulnerability_exports/exporters/csv_service.rb
• ee/app/graphql/mutations/vulnerabilities/create.rb
• ee/app/graphql/types/vulnerability_type.rb
• ee/app/models/ee/vulnerability.rb
• ee/app/models/vulnerabilities/finding.rb
• lib/gitlab/ci/parsers/security/common.rb
• lib/gitlab/ci/reports/security/finding.rb
• ee/app/services/security/ingestion/**

3. Adjust specs

Verification steps

1. Trigger a pipeline using a report that contains a vulnerability with a message property with a value different to the name. (example)
2. Go to the pipeline security report and confirm that the vulnerability name matches the name property, not message.
3. As above, for the vulnerability report.
4. As above, for the GraphQL query (instead of name, the title must match)
5. In the vulnerability report, click export. In the generated CSV, the Vulnerability column must match name. The Additional Info column must be empty.