* fix: Remove unused workspace routes in favor of list with filter
This consolidates the workspace routes into a single place.
It allows users to fetch a workspace by their username and
workspace name, which will be used by the frontend for routing.
* Fix RBAC
* Fix CLI usages
This changes all "coder workspace *" commands to root.
A few of these were already at the root, like SSH. The
inconsistency made for a confusing experience.
