Multiple bug fixes and feature additions

【Contents of fixes and function additions】
■Added a copy function to the shortcode list screen.
■The date of creation is displayed on the shortcode list screen.
■All types:
 →Added custom CSS and preview functions to to tabs.
 →Added the ability to set the body background color, text box, and text area background color.
■Form types:
 →Added the ability to retrieve the values entered in the form and use them in tags when setting up a reply mail.
 →Add a function to move to another page after clicking the “Send” button.
 →Fixed a bug in the select box.
 →Corrected the button display of the send confirmation screen.
 →Modify the format of the sent email.
 →Fixed a bug that the setting values of mail settings and confirmation mail are not saved.
■Adjusted the display and style.

The files that have been modified for this update are as follows
【Added files】
plugins/tcd-workflow/preview.php

【Modified files】]
plugins/tcd-workflow/admin.css
plugins/tcd-workflow/design-plus-contact-form.php
plugins/tcd-workflow/flow.php
plugins/tcd-workflow/form-list.php
plugins/tcd-workflow/form.php
plugins/tcd-workflow/languages/tcd-contact-form-ja.mo
plugins/tcd-workflow/languages/tcd-contact-form-ja.po
plugins/tcd-workflow/new-form.php
plugins/tcd-workflow/readme.txt
plugins/tcd-workflow/table.php

For details, please refer to the download site for purchasers of AGENT (tcd033).