net: http: Provide destination address in http replies

net_app_ctx maintains multiple net contexts(net_ctx). But when http
api's wants to reply or send some data, its always choose the first
net_context in the array, which is not correct always.

net_app_get_net_pkt_with_dst() api will select proper context
based on destination address. So with the help of new api in
net_app, http can select proper context and send packets. To
achieve this, desination address is provided in http_recv_cb_t
and http_connect_cb_t callbacks. Also chaged relevant API's to
provide destination address in http message preparation methods.

Signed-off-by: Ravi kumar Veeramally <ravikumar.veeramally@linux.intel.com>