Fix WP Approve User integration for v12+ three-state meta

[obenland]

Summary

WP Approve User v12 switched the wp-approve-user user meta from a boolean to a three-state string: 'approved', 'pending', or 'unapproved'. The integration's is_pending() check at core/includes/integrations/class-rcp-wp-approve-user.php:63 still treats the meta as a boolean:

return (bool) is_user_logged_in()
    && ! get_user_meta( $user_id, 'wp-approve-user', true )
    && ! user_can( $user_id, 'edit_pages' );

Every v12+ string is truthy, so ! $meta is always false. Pending and unapproved users surface as approved and gain access to content that should be restricted.

Fix

Compare the stored value against the canonical v12+ string ('approved') and the legacy '1' boolean still present on pre-v12 installs. Anything else is treated as pending. This is forward- and backward-compatible across WP Approve User versions.

return 'approved' !== $status && true !== $status && '1' !== $status;

Test plan

• Activate WP Approve User v12+, register a user (status 'pending'), log in as that user, and confirm they cannot view content gated by [restrict] or post-level RCP restrictions.
• Unapprove an approved user (status 'unapproved') and confirm they are blocked from restricted content on next page load.
• Approve a pending user via the RCP member-row "Approve" action and confirm they regain access.
• On a site running WP Approve User v11 or earlier (legacy boolean storage), confirm approve/unapprove still work — the '1' and empty-string code paths must keep functioning.