Support Terraform CLI Workspaces

[DanThePutzer]

Currently runs are pushed to and shown in the Pluralith dashboard individually.

When using Terraform CLI workspaces in CI one might run plans in the same Terraform project on multiple workspaces/environments with only slight differences and want to document/diagram all of them.

It would be great to show several plans happening in one CI run across multiple workspaces/environments grouped in the Pluralith dashboard and let the user select which workspace/environment they want to view in the UI (presumably through a dropdown).

Shoutout to @ethanculler for the feature suggestion!