add new osmo_sockaddr_from_str_and_uint() function

The function is basically a shortcut for getaddrinfo with storing the
output data into our 'struct osmo_sockaddr'.

Change-Id: I6b5c0bf8ca97e6358d992fb2ff45ffd53ba15197
Related: SYS#6657
diff --git a/tests/socket/socket_test.ok b/tests/socket/socket_test.ok
index 236c011..2b1c100 100644
--- a/tests/socket/socket_test.ok
+++ b/tests/socket/socket_test.ok
@@ -31,3 +31,6 @@
 Checking osmo_sockaddr_to_str_buf long IPv6
 Checking osmo_sockaddr_to_str_buf long IPv6 port
 Checking osmo_sockaddr_to_str_buf long IPv6 port static buffer
+Checking osmo_sockaddr_from_str_and_uint for 0.0.0.0
+Checking osmo_sockaddr_from_str_and_uint for ::
+Checking osmo_sockaddr_from_str_and_uint for 1.2.3.4