Define default behaviors for making HTTP requests within modules #3686

In the unstable MVP of procedures, we're being somewhat hand-wavy about certain behaviors of our HTTP API, particularly:

• Redirect following.
• Retries.
• The distinction between connect timeout and download timeout.

Our WASM languages use reqwest internally at this time, which seems to have sensible defaults. We also use a single shared timeout for both connect and download.

At some point in the future, we may want to expose a way to configure these things, something like a ctx.http.send_with_options(request, options). That's not what this ticket is about.

In this ticket, we should determine and document what our default behaviors are, and ensure that they are consistent between WASM languages and V8 languages.