Merge branch '522997-wiki-pages-should-have-a-category-for-filtering-in-to-do-list' into 'master'

Add a category for wiki page todos filtering in To-Do List

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/184148



Merged-by: Deepika Guliani <dguliani@gitlab.com>
Approved-by: Vamsi Vempati <vvempati@gitlab.com>
Approved-by: Deepika Guliani <dguliani@gitlab.com>
Co-authored-by: Piotr Skorupa <pskorupa@gitlab.com>