Implemented state remove command

[aleksanderaleksic]

Implemented the state remove command, with a lot of inspiration from the state move command

[hashicorp-cla]

All committers have signed the CLA.

[paultyng]

@aleksanderaleksic this mostly looks good to me, do you think you could also add an e2e test (see the tfexec/internal/e2etest directory). That will at least let it get exercised across multiple versions of TF to ensure its present and works in an expected way.

[aleksanderaleksic]

@paultyng Added a test now 👍🏻

[paultyng]

LGTM, would like to have @kmoe give a once over as well though.

[kmoe]

Thank you, looks good. One comment regarding parameter naming.