What UI Action is used to extract a code-stub from a REST message for server-side scripts?

The choice related to "Preview Script UI Action" is correct because it provides a way to extract a code-stub from a REST message specifically designed for use in server-side scripts. This UI Action allows developers to see and copy the relevant JavaScript code pieces that represent the response or request format from a configured REST message.

Utilizing the "Preview Script UI Action" streamlines the development process by ensuring that developers have the right structure and syntax for their server-side scripts when interacting with REST APIs. This is particularly helpful when integrating with external services, saving time, and minimizing errors in the coding process.

The other options do not pertain directly to extracting code stubs from REST messages in the context of server-side scripts. They may involve different functionalities or refer to actions that do not specifically address the needs described in the question. Therefore, the "Preview Script UI Action" stands out as the appropriate choice for the task at hand.