The formatter in `command/format/state.go`, when formatting a resource
with an aliased provider, was looking for a schema with the alias (ie,
test.foo), but the schemas are only listed by provider type (test).
Update the state formatter to lookup schemas by provider type only.
Some of the show tests (and a couple others) were not properly cleaning
up the created tmpdirs, so I fixed those. Also, the show tests are using
a statefile named `state.tfstate`, but were not passing that path to the
show command, so we were getting some false positives (a `show` command
that returns `no state` exits 0).
Fixes#21462