net: Use network byte order for in_addr.s_addr
Summary:
It is documented in the ip(7) manual page.
This is a backport of core#19991 [1/8]
https://github.com/bitcoin/bitcoin/pull/19991/commits/b3273cf4039d26e66ae58a8acb9d865461618d54
Test Plan: ninja all check-all
Reviewers: #bitcoin_abc, majcosta
Reviewed By: #bitcoin_abc, majcosta
Differential Revision: https://reviews.bitcoinabc.org/D10444