Improve 'prevent-xhr' — multiple requests

[AdamWr]

Related to - #261, but a bit different.

Steps to reproduce

1. Add this rule:

example.org#%#//scriptlet('prevent-xhr', '/advert')

2. Go to - https://example.org/
3. Run in console

const xhr_should_be_blocked = new XMLHttpRequest();
const xhr_should_not_blocked = new XMLHttpRequest();
xhr_should_be_blocked.open('GET', '/advert', true);
xhr_should_not_blocked.open('GET', '/test', true);
xhr_should_be_blocked.send(null);
xhr_should_not_blocked.send(null);

xhr_should_be_blocked.responseURL should returns 'https://example.org/advert', but it returns 'https://example.org/test'.

Screenshot

The problem is here:

Scriptlets/src/scriptlets/prevent-xhr.js

Line 197 in bb9c893

responseURL: { value: responseURL || xhrData.url, writable: false },

xhrData.url is from second request.
We could add something like thisArg.url = xhrData.url, here:

Scriptlets/src/scriptlets/prevent-xhr.js

Lines 129 to 131 in bb9c893

	} else if (matchRequestProps(source, propsToMatch, xhrData)) {
	thisArg.shouldBePrevented = true;
	}

and then use it in responseURL instead of xhrData.url.

[AdamWr]

Another issue is that xhr_should_not_blocked.getAllResponseHeaders() (same steps as in previous comment) throws error.
Uncaught TypeError: Cannot read properties of undefined (reading 'length')

Screenshot