[FE] Implement filtering functionality in the pipeline security dashboard

Why are we doing this work

Recently, with !61536 (merged) we started using the vulnerability_list.vue component in the Pipeline Security Dashboard. This list is backed by GraphQL and was already used in the Project, Group and Instance. Right now, it only displays the pipeline findings, but filtering was not implemented. This issue is about implementing the missing filtering functionality.

Steps to reproduce:

1. Fork a repository (such as https://gitlab.com/gitlab-examples/security/security-reports/)
2. Run the pipeline
3. Enable the feature flag: :pipeline_security_dashboard_graphql
4. Go to Project > CI/CD > Pipelines > Your Pipeline > Security Tab

Relevant links

Implementation plan

• frontend ee/app/assets/javascripts/security_dashboard/components/pipeline_findings.vue handles the query for fetching the findings. We just need to pass the filter parameters to the GraphQL query and update the graphql/queries/pipeline_findings.query.graphql file to support filtering.
• frontend Implement tests.