Have the `Create Environment` command present the user with `pyproject.toml` optional dependencies to install

[brettcannon]

pyproject.toml files can define a [project.optional-dependencies] table which lists extras that can be installed. We should offer a multi-select when running Create Environment so folks have a chance to install those extras.

For instance, if they have a test extra and they select it, we could do pip install -e .[test] to install it. Multiple extras can be added the comma-separated list.

[brettcannon]

Should make sure the flow from a UI perspective should be similar to whatever is chosen for #20277 .