A lot of commands used `c.Meta.flagSet()` to create the initial flagset for the command, while quite a few of them didn’t actually use or support the flags that are then added.
So I updated a few commands to use `flag.NewFlagSet()` instead to only add the flags that are actually needed/supported.
Additionally this prevents a few commands from using locking while they actually don’t need locking (as locking is enabled as a default in `c.Meta.flagSet()`.
This command serves as an alternative to the human-oriented list of workspaces for scripting use-cases where it's useful to know the _current_ workspace name.
We're shifting terminology from "environment" to "workspace". This takes
care of some of the main internal API surface that was using the old
terminology, though is not intended to be entirely comprehensive and is
mainly just to minimize the amount of confusion for maintainers as we
continue moving towards eliminating the old terminology.
Feedback after 0.9 was that the term "environment" was confusing due to
it colliding with several other concepts, such as OS environment
variables, a non-aligned Terraform Enterprise concept, and differing ideas
of "environment" within various organizations.
This new term "workspace" is intended to ease some of that confusion. This
term is not used anywhere else in Terraform today, and we expect it to not
be used in a manner that would be confusing within user organizations.
This begins a deprecation cycle for the "terraform env" family of commands,
instead moving to an equivalent set of "terraform workspace" commands.
There are some remaining references to the old "environment" concept in
the code, which will be cleaned up in a separate change. This change is
instead focused on text visible in the UI and wording within code comments
for the benefit of human maintainers of the code.
