uri: provide raw_content, parse json without double-decoding

Fixes #7586 
Regression potential:
 - `raw_content` is written to `dest` file instead of decoded `content`
 - `raw_content` doubles module reply
> `start-stop-daemon`

@jlaska  I've already removed start-stop-daemon and replaced it with `async` ansible task.
`async` also handles cleanup, although in an ugly way (timeout). I think it's good enough for tests. Am I wrong?