It displays a run header with link to web UI, like starting a new plan does, then confirms the run
and streams the apply logs. If you can't apply the run (it's from a different workspace, is in an
unconfirmable state, etc. etc.), it displays an error instead.
Notable points along the way:
* Implement `WrappedPlanFile` sum type, and update planfile consumers to use it instead of a plain `planfile.Reader`.
* Enable applying a saved cloud plan
* Update TFC mocks — add org name to workspace, and minimal support for includes on MockRuns.ReadWithOptions.