JS: Model Express json and jsonp methods

[asgerf]

No description provided.

[Copilot]

Pull Request Overview

This PR adds modeling for Express.js response methods json() and jsonp() to the CodeQL JavaScript library. These methods are commonly used to send JSON responses and set appropriate content-type headers.

• Adds new classes to model res.json() and res.jsonp() calls as header definitions and response send arguments
• Creates test cases to verify the modeling works correctly with Express routes
• Updates expected test results to include the new JSON response handling

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
javascript/ql/lib/semmle/javascript/frameworks/Express.qll	Adds ResponseJsonCall and ResponseJsonCallArgument classes to model Express json/jsonp methods
javascript/ql/test/library-tests/frameworks/Express/src/json.js	New test file with routes using res.json() and res.jsonp()
javascript/ql/test/library-tests/frameworks/Express/tests.expected	Updated expected test results to include the new JSON response modeling

[Napalys]

Looks good! 👍 I think Copilot's suggestion is correct regarding the docstring and we should change it.