Add policyAutoDismissed GraphQL field for vulnerabilities

What does this MR do and why?

When a vulnerability gets auto-dismissed by a vulnerability management policy, we want to display a badge in the activity column of the Vulnerability Report. For that, we need to expose this field in GraphQL.

References

• Depends on Add AutoDismissService for auto-dismiss policies (!214068 - merged)
• Frontend changes added in Add a badge for vulnerabilities auto-dismissed ... (!214879 - merged)
• Worker that triggers AutoDismissService based on SBOM vulnerability creation: Add `AutoDismissWorker` to trigger based on Vul... (!214531 - merged)
• Integration of AutoDismissService into IngestReportsService: Integrate AutoDismissService into IngestReports... (!214673 - merged)

Screenshots or screen recordings

End result with the frontend changes will look like this:

Before (or without FF)	After

How to set up and validate locally

1. In rails console enable the feature flag

   Feature.enable(:auto_dismiss_vulnerability_policies)

2. Create a project
3. Create an auto-dismiss policy:

   vulnerability_management_policy:
   - name: Auto-dismiss acceptable secrets
     description: Auto-dismiss secrets
     enabled: true
     actions:
     - type: auto_dismiss
       dismissal_reason: not_applicable
     rules:
     - type: detected
       criteria:
       - type: file_path
         value: ".env"

4. Add .gitlab-ci.yml with secret detection

   include:
   - template: Jobs/Secret-Detection.latest.gitlab-ci.yml    

5. Add two secrets in the main branch:
   1. .env:

      AWS_TOKEN=AKIAZYONPI3G4JNCCWGQ

   2. .env2:

      AWS_TOKEN=AKIAZYONPI3G4JNCCWGA

6. Wait until the pipeline on main finishes
7. In the rails console, run the service manually, passing the latest pipeline ID and the two vulnerability IDs:

   Vulnerabilities::AutoDismissService.new(Ci::Pipeline.find(<pipeline_id>), [vuln_1_id, vuln_2_id]).execute

8. Query the policyAutoDismissed field using GQL explorer:

   {
     project(fullPath: "<project-path>") {
       id
       vulnerabilities {
         nodes {
           id
           title
           policyAutoDismissed
         }
       }
     }
   }

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Related to #581388