Block editor and Customizer display avatars even when 'show_avatars' option is disabled

[ffffelix]

In two instances, avatars are displayed even when the site option show_avatars is disabled.

• Block editor: the avatar is passed in to $editor_settings on initial load by edit-form-blocks.php
• Customizer: outputs the avatar via WP_Customize_Manager->get_lock_user_data()

This is already handled correctly in the classic editor and in the Heartbeat AJAX handler for refreshing the post lock.

Adds checks for the show_avatars option before setting the avatar for post lock modals in the block editor and the Customizer.

Trac ticket: https://core.trac.wordpress.org/ticket/62081

[ffffelix]

Block editor with show_avatars disabled (before patch)

[ffffelix]

Block editor with show_avatars disabled (with patch)

[ffffelix]

Customizer with show_avatars disabled (before patch)

[ffffelix]

Customizer with show_avatars disabled (with patch)

[SergeyBiryukov]

In 59078:

Editor: Respect show_avatars option in block editor and Customizer.

This adds checks for the show_avatars option before setting the avatar for post lock modals in the block editor and the Customizer.

Follow-up to [41839], [53070].

Props ffffelix.
Fixes #62081.

Thanks for the PR! Merged in r59078.