GraphQL: Add retryable and cancelable to PipelineType

What does this MR do?

Adds the retryable and cancelable methods to PipelineType

query {
 project(fullPath: "gitlab-org/gitlab-shell") {
   pipeline(iid: 6) {
     retryable
     cancelable
     destroyable
   }
 }
}

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• [-] Separation of EE specific content

#238596 (closed)