How can I list all pages with their templates?

Using phpmyadmin (sql) you can run this query to get a list of all pages with its used template:

SELECT p.post_name, p.post_title, meta_key, meta_value FROM `wp_postmeta` INNER JOIN wp_posts p ON p.ID = post_id WHERE meta_key='_wp_page_template' ORDER BY meta_value, p.post_name

Rather than do this in PHP, you can do it with this mysql:

SELECT distinct meta_value FROM `wp_postmeta` WHERE meta_key='_wp_page_template'

I just needed it for a quick check so that I could clean up unused templates with the theme_page_templates filter.

https://codex.wordpress.org/Function_Reference/get_page_template_slug

a basic query to get all pages, sorted by title, then output page title and template file name:

$args = array(
    'post_type' => array( 'page' ),
    'order' => 'ASC',
    'orderby' => 'title'
    );
$the_query = new WP_Query( $args );
if ( $the_query->have_posts() ) {
    while ( $the_query->have_posts() ) {
        $the_query->the_post();
        echo '<p>'; 
        the_title();
        echo ' - ';
        echo get_page_template_slug(); 
        echo '</p>';
    }
    wp_reset_postdata();
}

I have tried flowing code to get all page with template, and worked perfect for me. this code purpose was to get all custom page template,as i was developed single page template.

$args = array(
    "post_type" => "page",
    "order" => "ASC",
    "orderby" => "menu_order"
);
$the_query = new WP_Query( $args );
if ( have_posts() ) {
    while ( $the_query->have_posts() ) {
        $the_query->the_post();
        ?>
        <div id="post-<?php the_ID() ?>">
        <?php
        global $post;
        $slug = $post->post_name;
        get_template_part("page", $slug);
        ?>
        </div>
        <?php
    }
    wp_reset_postdata();
}