Currently, the response tab for a request's detail in devtools does not
show the available data, this was due to how the content is being
structured (not the way firefox's devtools client expects it) and also
the body being discarded and not stored in the actor.
This PR stores the body in the actor , which is then retrieved in
`getResponseContent` and then use it to instantiate the new struct
`ResponseContentObj` which matches the format firefox's expects
Fixes: https://github.com/servo/servo/issues/38128
---------
Signed-off-by: uthmaniv <uthmanyahayababa@gmail.com>
Signed-off-by: Josh Matthews <josh@joshmatthews.net>
Co-authored-by: Josh Matthews <josh@joshmatthews.net>
