net: core: stable backports for 9.3 phase 1

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2188560 Depends: !2404 (merged)

A bunch of fixes from upstream, affecting the core networking implementation.

This also includes a couple of fixes for tun/tap, strictly tied to commit "net: add sock_init_data_uid()"

Signed-off-by: Paolo Abeni pabeni@redhat.com