nm-shared-utils: relax ovs ifname check to accept any (non-space) ASCII printable char

quoting 'man ovs-vswitchd.conf.db':
"The name must be alphanumeric and must not contain forward or backward
slashes."

OVS actually accepts a wider range of chars (all printable UTF-8 chars),
NetworkManager restricts this to ASCII char as it's a safer option for
now since OVS is not well documented on this matter.

https://bugzilla.redhat.com/show_bug.cgi?id=1788432

Fixes: e7d72a14f6 ('libnm-core: use different ifname validation function for OVS bridges, ports and interfaces')

shared/nm-glib-aux/nm-shared-utils.c

@@ -4097,11 +4097,14 @@ _nm_utils_ifname_valid_ovs (const char* name, GError **error)
 {
 	const char *ch;
 
+	/* OVS actually accepts a wider range of chars (all printable UTF-8 chars),
+	 NetworkManager restricts this to ASCII char as it's a safer option for
+	 now since OVS is not well documented on this matter.
+	 */
 	for (ch = name; *ch; ++ch) {
 		if (   *ch == '\\'
 		    || *ch == '/'
-		    || g_ascii_isspace (*ch)
-		    || !g_ascii_isalnum (*ch)) {
+		    || !g_ascii_isgraph (*ch)) {
 			g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
 			                     _("interface name must be alphanumerical with "
 			                       "no forward or backward slashes"));