Simplify `Page.On` event handling system for `Request` and `Response` handling

[inancgumus]

What

Enable the Page.On's existing event system to be used as event listening for Page.WaitForRequest|Response.

Why

The current Page.WaitForResponse:

• Deviates from the existing Page.On event system, which we perfected long ago:
• Unnecessarily creates its own event handling system, separate from our existing one.

By using Page.On's existing event handling, we can improve the maintainability of the browser module code and simplify its implementation of Page.WaitForRequest and related functions.

How

Similar to Playwright, we plan to add two methods:

• Page.addEventListener to register an event listener
• Page.removeEventListener to remove an event listener
• Page.waitForEvent to listen for a page event.
• Later on, removeEventListener can be used for implementing Page.RemoveEventListener 🎉
• Later on, waitForEvent can be used for implementing Page.WaitForEvent and many others 🎉

By using these two methods, we can reuse them from Page.On, Page.WaitForResponse, Page.WaitForRequest, and so on.

Plan

• Add Page.add|removeEventListener #5311
• Refactor pattern matcher #5314
• Add Page.waitForEvent by refactoring page event handling #5315
• Use the existing event system to listen for responses and requests
• Consolidate all request handling methods (e.g., onRequest)

Related

• Add waitForReponse in page #5002
• Implement Page.waitForRequest(urlOrPredicate[, options]) #4483
• Page.On #4232