Frontend: PMG GraphQL - Fetch stage by ID

For the GraphQL version of pipeline mini graph, we want to fetch the stage by ID. When the stage icon in the mini graph is clicked, this data will display in the dropdown.

This work was already started before we halted work on the pipeline mini graph in December 2023. The query exists behind a feature flag on master here. We simply need to build out the rest of the component for the GraphQL version of the pipeline mini graph.