Add 'Cancel all imports' button and confirmation dialog when importing projects from GitHub
<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Work on this issue](https://contributors.gitlab.com/manage-issue?action=work&projectId=278964&issueIid=385874) - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=385874) </details> <!--IssueSummary end--> The following discussion from !103934 should be addressed: - [ ] @xanf started a [discussion](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/103934#note_1209118861): (+5 comments) > @gdoyle could you please give us a hand with ~UX review? **non-blocking:** The [design](https://gitlab.com/gitlab-org/gitlab/-/issues/247325) included a Cancel imports button when you bulk import many projects. I didn't see that appear on the screen. Will this be done in a follow-up? ![Screenshot_2022-12-14_at_3.53.23_PM](https://gitlab.com/gitlab-org/gitlab/uploads/308c47da6610247d85b23f438345508c/Screenshot_2022-12-14_at_3.53.23_PM.png) ## Proposal - Add `Cancel all` button based on this [design](https://gitlab.com/gitlab-org/gitlab/-/issues/247325). - Add a confirmation modal when taking this action with the following text :point_down: > #### Cancel remaining imports? > > **6 repositories** are still importing. Imported files will be kept. You can reimport these repositories again later. > > `Continue importing` {-Cancel remaining imports-} ~"Technical Writing" review: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/103934#note_1211554229
issue