Portfolio shortcode: display extra CSS classes based on enabled sections

It would be great if the shortcode could display special CSS classes based on the enabled sections.

If we check a documentation page for the shortcode (https://wordpress.com/support/portfolios/portfolio-shortcode/), we can see that it provides options to display the following sections:
- Content;
- Types;
- Tags;
- Author;

For example, if the content is enabled then the container can have `.has-content` class.

Having these classes will allow to create different layouts based on enabled sections.

Start with the portfolio shortcode implementation and compare its section options with the linked portfolio shortcode documentation. Add a distinct CSS class for each enabled Content, Types, Tags, and Author section, then verify that the container classes change correctly when those options are enabled or disabled.

Written by the indexing model from the issue text.