Social Icons block can't be operated with the keyboard

[afercia]

Description

Discovered while working on #60044 / #60047

After inserting a first social link inside the Social Icons block, I couldn't find a way to add more links when using the keyboard.

Also, focus indication is some of the editing steps is missing.

Step-by-step reproduction instructions

• Edit a post, add a Social Icons block.
• At this point, focus is on the empty parent block. Screenshot:

• Press tab and observe focus moves to the 'Add block' plus icon button. Screenshot:

• Observe the focus indication is missing.
• Press Enter and a popover to add social links opens.
• Select one of the social links and press Enter.
• The first social link is added. Screenshot:

• Observe the focus indication is missing.
• At this point, I couldn't find a way to move focus again to the 'Add block' plus icon button, Tab or Arrows key do different things.
• The process requires to move focus to the parent block first. This isn't easy with the keyboard but can be done.
• From there:
  • Tab moves focus to the Settings panel. This is the expected behavior.
  • Arrow keys move focus to the inner blocks, which is the first social link.
  • Couldn't find any way to focus the 'Add block' plus icon button.

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]

The same issue occurs when adding Social links in a Navigation block. I couldn't find a way to mote keyboard focus to the 'plus' icon after adding a first social link:

[Mamaduka]

@afercia, the #59303 should improve situation a bit by making insert before and after shortcuts available for the inner blocks.