fix: set cookies when throwing redirect in handle

[eltigerchino]

fixes #8643

Adds headers and cookies to the response when using throw redirect in handle so that it behaves similarly to returning a new redirect Response in handle.

I'm sure there's a more elegant approach to this fix and the test, but I can't quite figure it out (this is my first time writing a test). Would appreciate any suggested changes.

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[dummdidumm]

Thank you! I think we need to apply the same logic to the case where it's a __data.json request (the if branch above the changed code)

[dummdidumm]

you can keep the redirect_response function and add the headers to it.

const response = redirect_response(..);
add_cookies_to_headers(..);
return response;

[eltigerchino]

I wanted to do it this way originally but wasn't sure if only cookies should be added or to include the headers from setHeaders() too.

I also didn't want a location header from setHeaders to overwrite the thrown redirect location.

Maybe I can extend the redirect_response() helper to optionally accept a headers option?
I noticed there were similar redirect responses in the file not using the helper just so that it could add other headers to it.

[dummdidumm]

Thank you!

[eltigerchino]

Thanks for the guidance!
Note that the current implementation only appends the set-cookie header and not other headers. But I forgot to change the changeset notes. My bad