Deprecate ButtonGroup component

[mirka]

What problem does this address?

The component does two things:

• Wrap the buttons in a role="group".
• Add styling to make it look like a segmented control.

As we can see from the usages in the Gutenberg app, role="group" is not semantically sufficient to make these buttons behave like a segmented control, and most consumers will not realize this. As such, most of our in-repo usages are inaccessible.

The outdated segmented control style is similar to the already deprecated RadioGroup, and is succeeded by the ToggleGroupControl style.

What is your proposed solution?

• Replace ButtonGroup usage with ToggleGroupControl #65339
• Soft deprecate the component. Fix: Add soft deperecation notice for the ButtonGroup component #65429

Consumers who want to wrap their buttons in a group can do that with a plain <div role="group">.

[hbhalodia]

Hi @mirka, I have raised the PR by adding the soft deprecation as expected on the issue. Let me know if we need to update anything else in the PR - #65429

Thank You,