The two-phase output properties change broke the ability to recover
from a failed replacement that yields pending deletes in the checkpoint.
The issue here is simply that we should remember pending registrations
only for logical operations that *also* have a "new" state (create or
update). This commit fixes this, and also adds a new step test with
fault injection to probe many interesting combinations of steps.
This PR just wires the `Package.Main` field to the Pulumi Service (and in subsequent PRs, the `pulumi-service` and `pulumi-ppc` repos).
@joeduffy , should we just upload the entire `package.Package` type with the `UpdateProgramRequest` type? I'm not sure we want to treat that type as part of part of our public API surface area. But on the other hand, we'll need to mirror relevant fields in N places if we don't.
