This adds a Revert two-step button to the JobVersions component for
not-current versions, which redirects to the overview on success. It
checks the job version before and after reversion to mitigate the edge
case where reverting to an otherwise-identical version has no effect, as
discussed in #10337.
It uses existing facilities for handling other errors and disabling the
button when permissions are lacking.
This is mostly a direct application of the ember-angle-brackets-codemod.
I manually restored newlines in multi-line component invocations, usually
preserving file line length except for now-non-positional link-to @route.
I needed to rename task to taskState in some cases to avoid Ember
Concurrency naming conflicts.
