Comment Moderator Role

// Role ID and the name shown on the Users screen.
$wpide_cmod_role = 'wpide_comment_moderator';
$wpide_cmod_name = 'Comment Moderator';

$wpide_cmod_add = function ( $roles ) use ( $wpide_cmod_role, $wpide_cmod_name ) {
    if ( ! $roles instanceof WP_Roles || isset( $roles->role_objects[ $wpide_cmod_role ] ) ) {
        return;
    }

    // edit_posts is needed to open the Comments screen; it only allows drafts of their own.
    $caps = array( 'read' => true, 'edit_posts' => true, 'moderate_comments' => true );

    $roles->roles[ $wpide_cmod_role ]        = array( 'name' => $wpide_cmod_name, 'capabilities' => $caps );
    $roles->role_objects[ $wpide_cmod_role ] = new WP_Role( $wpide_cmod_role, $caps );
    $roles->role_names[ $wpide_cmod_role ]   = $wpide_cmod_name;
};

$wpide_cmod_add( wp_roles() );
add_action( 'wp_roles_init', $wpide_cmod_add );

// Moderators may edit any comment, without needing edit rights on the post it belongs to.
add_filter( 'map_meta_cap', function ( $caps, $cap, $user_id ) use ( $wpide_cmod_role ) {
    if ( 'edit_comment' !== $cap ) {
        return $caps;
    }

    $user = get_userdata( $user_id );

    if ( $user && in_array( $wpide_cmod_role, (array) $user->roles, true ) ) {
        return array( 'moderate_comments' );
    }

    return $caps;
}, 10, 3 );

// Keep the Posts and Tools menus out of their way.
add_action( 'admin_menu', function () use ( $wpide_cmod_role ) {
    if ( in_array( $wpide_cmod_role, (array) wp_get_current_user()->roles, true ) ) {
        remove_menu_page( 'edit.php' );
        remove_menu_page( 'tools.php' );
    }
}, 99 );