This change, part of pulumi/lumi#90, overhauls quite a bit of the
core resource, planning, environments, and related areas.
The biggest amount of movement comes from the splitting of pkg/resource
into multiple sub-packages. This results in:
- pkg/resource: just the core resource data structures.
- pkg/resource/deployment: all planning and deployment logic.
- pkg/resource/environment: all environment, configuration, and
serialized checkpoint structures and logic.
- pkg/resource/plugin: all dynamically loaded analyzer and
provider logic, including the actual loading and RPC mechanisms.
This also splits the resource abstraction up. We now have:
- resource.Resource: a shared interface.
- resource.Object: a resource that is connected to a live object
that will periodically observe mutations due to ongoing
evaluation of computations. Snapshots of its state may be
taken; however, this is purely a "pre-planning" abstraction.
- resource.State: a snapshot of a resource's state that is frozen.
In other words, it is no longer connected to a live object.
This is what will store provider outputs (ID and properties),
and is what may be serialized into a deployment record.
The branch is in a half-baked state as of this change; more changes
are to come...