Move fork project form request to api/projects_api.js
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The following discussion from !53544 should be addressed:
- [ ] @vitallium started a [discussion](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/53544#note_520037271): (+1 comment)
> **nitpick (non-blocking):** WDYT about moving this request to `api/projects_api.js` for consistency?
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