Add workflow events to project graphql

What does this MR do and why?

Add workflow events to project graphql

Continues the work in !196164 (merged)

References

#553391 (closed)

How to set up and validate locally

1. Set up Duo Workflow in GDK
2. Create local workflows in remote execution. Workflows need to have checkpoints/events to show up with this query. You can also generate workflows using bundle exec rake "gitlab:duo_workflow:populate[50,20,user@example.com,gitlab-org/gitlab-test,web]"
3. Open graphql_explorer
4. Check that the current user can see a remote execution workflow that the user created
5. Check that the user can see a remote execution workflow that another user created, within the same project.
6. The query will not return workflows that are within another project (i.e. $workflowIdOther is not in $projectPath)

query getEvents($workflowIdOther: AiDuoWorkflowsWorkflowID!, $projectPath: ID!){
  project(fullPath: $projectPath){
    duoWorkflowEvents(workflowId: $workflowIdOther){
      nodes {
        checkpoint
        errors
        workflowGoal
        workflowStatus
        workflowDefinition
      }
    }
  }
}

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