Page builder feature addition and multiple fixes

【Details of fixes and feature additions】
■Added page builder function.
■Fixes to resolve errors in PHP7 environment.
■Adjusted the display style of the description of Contents 1 > Box 2 on the top page when displayed on a smartphone.
■Fixes to enable password protection settings on pages created using fixed page templates 1 to 3.
■Fixed the display collapse of the post list screen when logging in to the admin screen from a smartphone.
■Fixed structured markup in breadcrumb list.

The following are the files that have been modified for this update.
【Corrected files】
admin/css/my_admin.css
breadcrumb.php
editor-style-01.css
functions.php
functions/repeater.php
languages/ja.mo
languages/ja.po
page/template1.php
page/template2.php
page/template3.php
responsive.css
style.css
【Added files】
editor-style-02.css
pagebuilder folder
pagebuilder/assets
pagebuilder/assets/admin
pagebuilder/assets/admin/css
pagebuilder/assets/admin/css/admin.css
pagebuilder/assets/admin/css/admin_bk.css
pagebuilder/assets/admin/css/media-field.css
pagebuilder/assets/admin/css/repeater.css
pagebuilder/assets/admin/js
pagebuilder/assets/admin/js/admin.js
pagebuilder/assets/admin/js/editor.js
pagebuilder/assets/admin/js/googlemap.js
pagebuilder/assets/admin/js/jscolor.js
pagebuilder/assets/admin/js/media-field.js
pagebuilder/assets/admin/js/repeater.js
pagebuilder/assets/css
pagebuilder/assets/css/pagebuilder.css
pagebuilder/assets/css/slider.css
pagebuilder/assets/css/tab.css
pagebuilder/assets/img
pagebuilder/assets/img/slider_arrow1.png
pagebuilder/assets/img/slider_arrow2.png
pagebuilder/assets/js
pagebuilder/assets/js/slider.js
pagebuilder/assets/js/tab.js
pagebuilder/modules
pagebuilder/modules/catchcopy.php
pagebuilder/modules/editor.php
pagebuilder/modules/googlemap.php
pagebuilder/modules/headline.php
pagebuilder/modules/image.php
pagebuilder/modules/includes.php
pagebuilder/modules/includes/jscolor.php
pagebuilder/modules/includes/media_field.php
pagebuilder/modules/includes/repeater.php
pagebuilder/modules/includes/slider.php
pagebuilder/modules/tab.php
Pagebuilder/pagebuilder.php
【Deleted files】