[cli] Fix vc dev proxy to upstream frontend dev server

[styfle]

This PR fixes a longstanding issue introduced in #3673 that prevents routing properties from applying to the framework's upstream dev server.

This mimic's the older proxy logic used in build matches here:

vercel/packages/now-cli/src/util/dev/server.ts

Lines 1535 to 1539 in 5035fa5

	const origUrl = url.parse(req.url || '/', true);
	delete origUrl.search;
	origUrl.pathname = dest;
	Object.assign(origUrl.query, uri_args);
	const newUrl = url.format(origUrl);

• Related to Now CLI 17.0.3 seems to ignore rewrites in dev #3777
• Related to [next] Fix nextjs routes in vercel dev #4510