Add additional check for remote flows

What does this MR do and why?

This MR adds an additional check to ensure Duo Remote Flows is enabled.

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Open GDK GraphQL explorer and execute:

query DuoWorkflow {
  project(fullPath: "gitlab-duo/test") {
    id
    duoWorkflowStatusCheck {
      enabled
      remoteFlowsEnabled
    }
	}
}

2. Open project or group settings and disable remote flows
3. Execute the query again and notice that remoteFlowsEnabled is now true.

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #569907 (closed)