http.server: No longer enfore JSON encoding for body

http.server: No longer enfore JSON encoding for body

The HTTP layer shouldn't care about the contents of the request data or
responses. This requires further changes in the RAPI code to handle client
requests correctly.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>