[BE] Extend GraphQL Ci::PipelineType to filter Security Report Findings based on State

Why are we doing this work

This is the backend work to be used by the UI as described in #331401 (closed). The pipeline security tab looks MOSTLY the same as the project/group/Security Center vulnerability reports, but it is implemented using entirely different code/endpoints. One exception is that the "hide dismissed" toggle that exists today on the pipeline security tab will be displayed as a State dropdown (which is aligned with the other vulnerability reports). Currently, the only options available in the dropdown will be Dismissed & Detected, but over time that list may expand.

Relevant links

• Frontend Issue

Non-functional requirements

• Documentation: Update GraphQL documentation
• Testing: Add/update GraphQL specs for the new type

Implementation plan

• Add state argument in ee/app/graphql/resolvers/pipeline_security_report_findings_resolver.rb so that we can filter by state with GraphQL
• Add the ability to filter by state in ee/app/finders/security/pipeline_vulnerabilities_finder.rb (note: there is a filter by scope in this file which just include findings with dismissed state or without dismissed state but we want here the filter which will filter by any state or array of states)