Clean up child components props for UnresolvedDiscussions vue component
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Passing down the entire store is unnecessary for some child components. (see https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/17866/diffs#8711bea194ab9a71a0cb2107c794d2108bb8f258_10_10). The comment was initially added by @filipa in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/17727/diffs#67c7dac258d3bde56543fd43d088f0914c6b50d3_25_10. Thanks Filipa!
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