RTL paragraph: 'Left to right' toolbar menu missing label and selected state semantics

[afercia]

Description

When the admin language is a Right-To-Left language, the Paragraph block toolbar shows an additional dropdown menu to give users the ability to set the text direction to Left-To-Right:

• The toggle button is unlabelled: there's no text or aria-label to provide the button name.
• When activated, the 'Left to right' menu item is highlighted only visually. There's no semantics to indicate its selected state. This menu item should have a role="menuitemcheckbox" and an aria-checked="false/true" attribute.

Step-by-step reproduction instructions

• Set the WordPress to a RTL language.
• Edit a post and add a Paragraph block.
• Select the block to make its toolbar appear.
• Inspect the toggle button that is placed on the left of the 'Align' button and observe it's unlabelled.
• Click the button to open the dropdown menu.
• Inspect the 'Left to Right' menu item button: observe there's no aria-checked=false attribute.
• Click 'Left to Right': the Paragraph text is now set to LTR and the menu closes.
• Open the menu again.
• Inspect the 'Left to Right' menu item button: observe there's no aria-checked=true attribute.

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[afercia]

Fixing the ParagraphRTLControl would be pretty simple:

• Pass a label prop with meaningful text to ToolbarDropdownMenu.
• Pass role: 'menuitemcheckbox' to the only control in the controls prop array.

However, I'm not sure a dropdown menu with only one menu item is the best option in the first place. Users are forced to click twice to activate this settings, while a simple button would require just one click.

[afercia]

Looks like this control wrapper used to be a ToolbarGroup and changed to DropdownMenu in #29863. Later, it changed to a ToolbarDropdownMenu. That may explain the lack of a label and semantic state, as the ToolbarGroup used to render a toggle button with a label and an aria-pressed state: