MEDIUM: server: merge srv_update_addr() and srv_update_addr_port() logic

MEDIUM: server: merge srv_update_addr() and srv_update_addr_port() logic

Both functions are performing the similar tasks, except that the _port()
version is doing a bit more work.

In this patch, we add the server_set_inetaddr() function that works like
the srv_update_addr_port() but it takes parsed inputs instead of raw
strings as arguments.

Then, server_set_inetaddr() is used as underlying helper function for
both srv_update_addr() and srv_update_addr_port() to make them easier
to maintain.

Also, helper functions were added:
 - server_set_inetaddr_warn() -> same as server_set_inetaddr() but report
   a warning on updates.
 - server_get_inetaddr() -> fills a struct server_inetaddr from srv

Since the feedback message generation part was slightly reworked, some
minor changes in the way addr:svc_port updates are reported in the logs
or cli messages should be expected (no loss of information though).