Introduce new filter "render_block_core_navigation_link_allowed_post_status"

[Chrico]

This PR introduces a new Filter for rendering the "Navigation Link"-Block to whitelist post_status to not restrict the output to only "public" post_status.

See more information in: #33215

Why?

Since Gutenberg 9.8.0 (see commit: 1936a04 | issue: #27207) the "Navigation Link"-Block limits the output to only "public" post_status.

While it is possible to hook into WP_Query and the WP_REST_Post_Search_Handler via rest_post_search_query to extend the $query_args with custom post_status in the REST Response, the rendering part will still limit to post_status = "publish.

With this new filter render_block_core_navigation_link_allowed_post_status it is now possible to also whitelist multiple post_status for rendering in frontend.

Testing Instructions

0. You need to have at least 1 Post which is post_status = "private".
1. Add a new mu-plugin which hooks into following:

add_filter( 
    'render_block_core_navigation_link_allowed_post_status', 
    static function(array $postStatus): array {
        $postStatus[] = 'private';

        return $postStatus;
} );

add_filter( 
    'rest_post_search_query', 
    static function( array $queryArgs): array {
        $postStatus = $queryArgs['post_status'] ?? [];
        $postStatus[] = 'private';

        $queryArgs['post_status'] = $postStatus;

        return $queryArgs;
} );

2. Create a new Page with "Navigation Block" and search for 0. the Post with post_status = "private" and insert
3. Save Page and go to frontend -> "private Post"-link is rendered.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

If you're merging code through a pull request on GitHub, copy and paste the following into the bottom of the merge commit message.

Co-authored-by: Chrico <chrico@git.wordpress.org>

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.