Tailor "Restart All Builds" for the complex realities of modern build restart rules
Fixes T13348. Currently, the Harbormaster UI shows "Restart All Builds", but it really means "Restart Restartable Builds", which is often fewer than "All" builds (because of autobuilds, permissions, and/or configuration).
Remove the misleading term "All" and make the workflow preview exactly which builds will and will not be affected, and why.
Reviewed By: amckinley
Maniphest Tasks: T13348
Differential Revision: https://secure.phabricator.com/D20679