In refactoring the force push code when implementing force push
for the Terraform remote backend, a bug was introduced that
meant that backends that don't implement the EnableForcePush
method would still have their state validated. This commit
fixes that, and adds test coverage such that there is a separate
mockRemoteClient that has this method implemented.
Most of the state package has been deprecated by the states package.
This PR replaces all the references to the old state package that
can be done simply - the low-hanging fruit.
* states: move state.Locker to statemgr
The state.Locker interface was a wrapper around a statemgr.Full, so
moving this was relatively straightforward.
* command: remove unnecessary use of state package for writing local terraform state files
* move state.LocalState into terraform package
state.LocalState is responsible for managing terraform.States, so it
made sense (to me) to move it into the terraform package.
* slight change of heart: move state.LocalState into clistate instead of
terraform
