New features

Changes since 1.0.0-alpha1:

• Issue #3132047 by mandclu: Simulate tab in Layout Builder
• Issue #3132024 by mandclu: Add icons for sections tray

Most of the improvements in this release are within layout builder: the Tabs section option now has an icon, and each block in the section shows a tab that acts as a preview of how the title will be rendered. Also, we now use the same active state class as core, so css styling will be inherited. As a result, the js was updated, so be sure to clear your caches.

Release addresses following issues:

Compared with alpha2:
- Many bugs fixes and issues tidied.
- Form moved a bit, to increase clarity and enable access to Fields UI;
- Listing views replaced and exposed filters improved;
- Code style improved.

Test framework is there but needs a lot of work. Failures are of tests not code at this point. Help requested.

First release.
Compatible with Drupal 9.