MR: Pending <!-- NOTE: For context on MR heading, see: https://handbook.gitlab.com/handbook/engineering/devops/dev/create/remote-development/index.html#relationship-of-issues-to-mrs --> ## Description As part of our [new designs for Workspaces](https://gitlab.com/groups/gitlab-org/-/epics/18674), we need the frontend to display merge request information in expanded workspace cards, and for that we need to add a `relatedMergeRequests` field to the existing Workspace GraphQL type and implement its resolver. ## Acceptance criteria - [ ] Add `relatedMergeRequests` field definition to existing Workspace GraphQL type - [ ] Implement resolver method that fetches open merge requests on the same branch from the same project - [ ] Return relevant MR fields needed for the designs - [ ] Add proper authorisation checks to ensure user can view the merge requests - [ ] Add error handling for cases where project or MR data is unavailable - [ ] Update GraphQL field documentation with examples ## TODO: Implementation plan <!-- NOTE: Feel free to expand with more sections and headers as needed --> <!-- DO NOT TOUCH BELOW -->