DAR-1243 Implement changes to the UI repo API

Another part of work on styleguide:
* removed unneeded files/placeholders,
* renamed `UIStyleguideComponents.class.php` to `StyleguideComponents.class.php`,
* moved `StyleguideComponents.class.php` to helpers subdirectory,
* changes in `Factory` class: renamed few methods and made them more reusable,
* removed quite a few methods in `StyleguideComponents` class.

TODO: Encapsulate component's messages and dynamically include them