Make ExecuteJavascriptMiddleware handle requests

[Fadarrizz]

This PR aims to close #239. By letting the middleware handle a request instead of a response and setting the response on the request, we ensure the request is only sent once.

Besides the fact that handling requests instead of responses saves a request, it also make sense for this middleware to handle the request instead of the client, since the request is send with the middleware.

One could say that a separate client should be created for sending Javascript requests and one would have a point in my honest opinion, but it's quite difficult to create Php responses from Browsershot/Puppeteer. Therefore, the changes in this PR offer a middleground.

[ksassnowski]

I see your point and the implementation looks fine to me. I still have to check if skipping the client could have any unintended consequences for users. I don't think it does since the Downloader still calls onResponseReceived for requests that had their response set by one of the middlewares.

[ksassnowski]

Please rebase your branch on top of the current main branch. That should get rid of most of the pipeline errors. Don't worry about the commitlint action. I can change the commit message when merging.

[Fadarrizz]

Thanks for taking the time to look at this PR, @ksassnowski.

I agree with your point and I don't think it will pose any issues for users. The only case I can think of is users that rely on both the client and the middleware, but I can't see why someone would need this.