Toggle [ci skip] from MR

I would love to be able to toggle [ci skip] from an MR, rather than per-commit. https://docs.gitlab.com/ee/ci/yaml/README.html#skipping-jobs

As a contributor on GitLab, especially as a member in any paid group, I am concerned with my usage of CI minutes and recognise that the whole team is responsible for efficiently using CI minutes.

I think it would be much easier to offer a toggle in the MR widget to temporarily disable CI. We could also offer a default setting to start every branch with CI toggled off. When CI is toggled back on, a pipeline is started on the latest commit.