Ultimate Member - User Bookmarks 2.1.5

* Fixed: Security vulnerability related to the 'user_id' parameter in AJAX requests
* Fixed: The "Add Folder" block displaying in the profile tab
* Tweak: Added animation for buttons while waiting for AJAX response

* Templates required update:

- buttons/add.php
- buttons/remove.php
- profile/folder-view.php

* Cached and optimized/minified assets(JS/CSS) must be flushed/re-generated after upgrade

* Added: "Create default folder" feature
* Fixed: "Add folder" button appears in other users' profiles
* Fixed: Extension settings structure

* Templates required update:

- profile/folder-view.php
- profile/folder-view/add-folder.php

* Fixed: XSS vulnerabilities
* Tweak: UM Dropdown.js scripts updated
* Deprecated: `profile/edit-folder/form.php` template - it's unusable duplicate of `profile/edit-folder.php`