Navigating straight to an image, PDF, or other resource could not read the
main response body over CDP, and Page.frameNavigated always reported
text/html.
Two problems: the main resource's body was stored under its internal
request id, but the client sees it as the navigation loaderId (Chrome's
requestId === loaderId convention), so Network.getResponseBody(loaderId)
missed. And binary bodies were stored as UTF-8-lossy text, corrupting the
bytes. Alias the stored body to the loaderId, store non-text-like content
types (images, PDF, octet-stream) base64, and report the response's real
Content-Type in frameNavigated. HTML pages are unchanged.
Fixes#340.
SGavrl
630f9894f6