Update Repo ref switcher to use Vue ref_dropdown
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We have a Vue [ref_dropdown](https://gitlab.com/gitlab-org/gitlab/blob/2951ca86718f96707da0e7d47dc61dc3d3cc65c8/app/assets/javascripts/pipeline_new/components/refs_dropdown.vue) component, let's update the current ref switching (which is in HAML) in the Repo view to use that instead:
<img src="/uploads/c554b0e6f0811978ed4cd1c76fc81135/image.png" height="300px">
## Info on the Ref Dropdown component
The Vue `ref_dropdown` component was introduced in this MR https://gitlab.com/gitlab-org/gitlab/-/merge_requests/55394
<img src="/uploads/558363a00a2babac52b57ef5d82e733d/image.png" height="300px">
## Proposal
I think this issue will need to be tackled iteratively and here are my suggested steps:
1. Create a shared component from the `ref_dropdown` component built for the pipeline
1. Used this shared component for the repository page
2. Update the pipeline ref_dropdown to use this shared version (might want to get the Verify team involved here)
issue