Ingest vulnerability_names of vulnerability_reads

What does this MR do and why?

New ingestion logic to ingest vulnerability names.

We intend to use this column for the filtering by identifier feature tracked in #432419 (closed)

Old column(identifier_external_ids) has to be abandoned and the removal is tracked in #479531 (closed). See implementation plan in #460080 (closed)

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Import the project from here into local without this MR change.
2. Run pipeline on the master branch, this should populate the identifiers and the project.vulnerability_reads.pluck(:identifier_names).first(10) should have empty array values.
3. With the ingestion change from this MR, run a pipeline and project.vulnerability_reads.pluck(:identifier_names).first(10) should have the identifier_names populated.

Related to #460080 (closed)