Refactor redirects to use tower-http

[seanmonstar]

reqwest supports defining redirect policies, and provides a few common ones. That support was later ported to tower_http::follow_redirect. To reduce duplication, and to make sure the tower-http code has all the improvements reqwest gets, we should just make reqwest depend on the one from tower-http.

Note: the public APIs are a little different. To prevent a breaking change, we should make the refactor simply internal.