* terraform: remove redundant code
NodeDestroyResourceInstance is never instantiated with a DeposedKey of anything other than states.NotDeposed, so the deleted code is never run. Deposed objects get a NodeDestroyDeposedResourceInstanceObject instead.
* tfdiags: add helper func
* configs: introduce removed block type
* terraform: add forget action
* renderer: render forget actions
* terraform: deposed objects can be forgotten
Deposed objects encountered during planning spawn
NodePlanDeposedResourceInstanceObject, which previously generated a
destroy change. Now it will generate a forget change if the deposed
object is a forget target, and a destroy change otherwise.
The apply graph gains a new node type,
NodeForgetDeposedResourceInstanceObject, whose execution simply removes
the object from the state.
* configs: add RemoveTarget address type
* terraform: modules can be forgotten
* terraform: error if removed obj still in config
* tests: better error on restore state fail
* Update CHANGELOG.md
