MR Widget Pipeline - Real-time
### What
Let's make the `app/assets/javascripts/vue_merge_request_widget/components/mr_widget_pipeline.vue` real-time and in-sync with the true pipeline status! In https://gitlab.com/gitlab-org/gitlab/-/merge_requests/225321 we added stage based subscription for the mini-graph. So the stages are in-sync and quick, now we just need the upstream overall stage status in-sync.
{width=900 height=525}
### Technical details
1. Do we add the subscription and query directly in `app/assets/javascripts/vue_merge_request_widget/components/mr_widget_pipeline.vue` ? Or somewhere upstream?
2. What do we need to remove upstream MR pipeline status wise?
3. Put this behind a feature flag `mr_widget_pipeline_real_time`
issue