Auto-Remediation - Show available solutions in Vulnerability Report - Add filtering by Merge Requests

Parent issue #258814 (closed)

We need to add filtering capabilities to our GraphQL API to filter vulnerabilities by created MR with fix.

We need to support the next query:

{
  project(fullPath: "some_project") {
    vulnerabilities(hasMergeRequest: true) {
       ...  
    }
  }
}

Implementation plan

Implementation is blocked right now by our data model. Right now vulnerabilities and their merge requests are connected with the Feedback model and that prevents us from implementing efficient filtering. We need to wait till #324859 (closed) is implemented