Make runners within project's and groups visible and a first class citizen

Problem(s)

• Currently the runners are placed in the settings menu within the CI/CD page. This makes it so that runners are only visible to masters of the project.
• Runners are a big deal to gitlab's CI/CD but are at the same time very secluded/not visible.
• Runners pages everywhere are a neglected piece of UI, which is used a lot by certain people. Having it be in the settings pages, makes it harder to reach/find (cc: @marin).
• It's currently hard to gauge for people why their job is pending.. when all runners are already busy

Proposal

• We are currently thinking of removing the jobs page which actually should be a deprecated view https://gitlab.com/gitlab-org/gitlab-ce/issues/34666
• https://gitlab.com/gitlab-org/gitlab-ce/issues/10244 Introduces group runners

Last CI/CD meeting we spoke about the possibility of replacing, rather than removing the jobs view, with a dedicated runners page (which still meets the usecase of being able to navigate directly to your running job).

This way runners would become visible to a lot more people alleviating the problems mentioned above. By replacing the jobs view with the runners view, we can give people a second way to navigate to their jobs, which actually makes sense.

We could do this for both projects as well as groups.