Local Scope entries in new Hierarchical Action List.

[akavel]

Pull Request Description

Make the local scope components available to the Component Browser through component::List (previously known as "Hierarchical Action List"). (See the Local Scope Section in the Design Doc for more details.)

https://www.pivotaltracker.com/story/show/181869186

Important Notes

• Note: the PR description does not include a screencast due to the changes in this PR not having any visual effect at this moment. The result of this PR's changes would be only observed in the Component Browser, but the Component Browser is not merged yet. As described in the task's Acceptance Criteria, the changes in this PR are currently only covered by tests.
• The component::group::Data::new_empty_visible constructor was renamed to from_name_and_id and changed to set the visible field to a default value. All known code paths appear to call the update_sorting_and_visibility method before checking the value of the visible field, so setting the value to true when creating the object does not seem needed.

[ci no changelog needed]

Checklist

Please include the following checklist in your PR:

• The documentation has been updated if necessary.
• All code conforms to the
  Scala,
  Java,
  and
  Rust
  style guides.
• All code has been tested:
  • Unit tests have been written where possible.
  • If GUI codebase was changed: Enso GUI was tested when built using BOTH
    ./run ide dist and ./run ide watch.