Refactor to remove global `mrWidgetData` object
The following discussion from !15114 should be addressed:
- [ ] @winh started a [discussion](https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/15114#note_203890942): (+3 comments)
> To be honest, I find this way of passing data to the frontend a little weird. Given that you only followed the existing pattern here, I consider it out of scope to change here.
>
> If you agree, we can create a follow-up issue to further discuss. Otherwise feel free to just ignore this comment. :smiley:
issue