basic: split ifname related calls from format-util.h into format-ifname.h

This way we don't have to pull in net/if.h into format-util.h.

This is supposed to address https://github.com/systemd/systemd/pull/32212#discussion_r1755639881

No actual code changes, just a .c/.h file split-up.

src/network/networkctl-dump-util.c

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include "format-util.h"
+#include "format-ifname.h"
 #include "in-addr-util.h"
 #include "local-addresses.h"
 #include "networkctl-dump-util.h"

src/network/networkctl-misc.c

@@ -5,7 +5,7 @@
 #include "bus-error.h"
 #include "bus-locator.h"
 #include "fd-util.h"
-#include "format-util.h"
+#include "format-ifname.h"
 #include "netlink-util.h"
 #include "networkctl.h"
 #include "networkctl-misc.h"

src/network/networkd-link.c

@@ -24,7 +24,7 @@
 #include "event-util.h"
 #include "fd-util.h"
 #include "fileio.h"
-#include "format-util.h"
+#include "format-ifname.h"
 #include "fs-util.h"
 #include "glyph-util.h"
 #include "logarithm.h"

src/network/wait-online/link.c

@@ -3,7 +3,7 @@
 #include "sd-network.h"
 
 #include "alloc-util.h"
-#include "format-util.h"
+#include "format-ifname.h"
 #include "hashmap.h"
 #include "link.h"
 #include "manager.h"