BE: Add policy_auto_dismissed to vulnerability report ES

Why are we doing this work

Users should be able to filter the Vulnerability Report by auto-dismissed vulnerabilities.

Relevant links

Non-functional requirements

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

Implementation plan

Review the approach taken for policy_violations filter and follow that pattern also for auto-dismissed flag.

Related MRs:

• Add policy violations field to Vulnerabilities ... (!207560 - merged)
• Adds policy_violations to vulnerability reference (!207638 - merged)
• Add policy violations to vulnerability graph api (!207947 - merged)
• Update vulnerability report docs (!210993 - merged)

Verification steps