Improve the DocumentBar post type label for the Homepage and Posts Page cases

[afercia]

Description

#65170 added a 'post type label' to the DocumentBar and removed the type icon to provide a clearer information about the object being edited. So far so good. Screenshot:

There are at least two edge cases though where other parts of the UI use a special label for the object being edited: The 'Homepage' and 'Posts Page' pages.

In this cases, while the DocumentBar still says just 'Page', the PostCardPanel in the Settings panel adds a more specific label to these special pages.

As such, users see two inconsistent pieces of information, which is confusing, and may think something is going wrong.

Screenshots:

I'd suggest to provide a consistent information and make the Document Bar handle these special cases by providing a consistent label:

• Homepage
• Posts Page

Step-by-step reproduction instructions

• Go to the wp-admin Reading Settings.
• Set your homepage to display a static page.
• Set a Posts page.
• Go to the Site editor > Pages.
• Select either the page used tor the homepage or the one used tor the posts page.
• Observe the Document Bar label is 'Page'.
• Observe the Post card in the settings panel uses a more specific label: 'Homepage' or 'Posts page'.

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]

Noting that the PostCardPanel uses some hardcoded checks to determine the label based on isFrontPage or isPostsPage.

A similar check is in place in usePostFields, which is is used in the data views posts list:

Instead of hardcoding a new, third check I'd suggest to explore how to abstract this logic into a small utility and reuse it where needed.