Dialog subtitle support in additional to prehead

[origami-z]

Area

UI Components

The problem

It would be nice to have an option to display some text at the bottom of Dialog header, similar to existing prehead option.

Guidance from my Content team:

• Preheaders are often used to introduce a section or draw attention to important information. They're not necessarily related to titles or subtitles.
• A subtitle, on the other hand, is a secondary text element that provides additional information or context to the main title. Subtitles can be used to provide a brief description, clarify the main title, or provide further details about the content of the design.

On top of #3601

The solution

Alternatives and examples

Add subtitle to body section of Dialog

Are you a JPMorgan Chase & Co. employee?

• [X] I am an employee of JPMorgan Chase & Co.