Move pipelines page to GraphQL

Let's move our Pipelines list view over to GraphQL 🎉

All components related to this feature live under app/assets/javascripts/pipelines/components. Soon to be grouped under a common directory app/assets/javascripts/pipelines/components/pipelines_list after this MR is merged.

This Vue app is quite large and has a lot of moving parts. So I would advise us to tackle moving pipelines_filtered_search.vue first and then the rest of the app. You can view that issue here #223267 (closed)

It may be a good idea to just introduce a stale GraphQL implementation that is not used by any feature yet into the codebase and quietly move bits of functionality to GraphQL. Or we could even do the work behind a flag.

You can view some more details in this comment around where things live and an example GraphQL query

Screenshot