libnm: pass around property_info instead of property_idx in NMSetting API

Various NMSetting API would accept a property_idx parameter. Together
with the NMSettInfoSetting instance, this was useful to find the actual
NMSettInfoProperty instance.

The idea was, to provide the most of the functionality. That is, if you
might need the property_idx too, you had it -- after all, the
property_info you could lookup yourself.

However,

- literally zero users care about the property_idx. The care about
  the property_info.

- if the user really, really required the property_idx, then it
  is a given that it can be easily computed by

     (property_info - sett_info->property_infos)

src/libnm-core-impl/nm-setting-bridge.c

@@ -1315,19 +1315,19 @@ verify(NMSetting *setting, NMConnection *connection, GError **error)
 }
 
 static NMTernary
-compare_property(const NMSettInfoSetting *sett_info,
-                 guint                    property_idx,
-                 NMConnection *           con_a,
-                 NMSetting *              set_a,
-                 NMConnection *           con_b,
-                 NMSetting *              set_b,
-                 NMSettingCompareFlags    flags)
+compare_property(const NMSettInfoSetting * sett_info,
+                 const NMSettInfoProperty *property_info,
+                 NMConnection *            con_a,
+                 NMSetting *               set_a,
+                 NMConnection *            con_b,
+                 NMSetting *               set_b,
+                 NMSettingCompareFlags     flags)
 {
     NMSettingBridgePrivate *priv_a;
     NMSettingBridgePrivate *priv_b;
     guint                   i;
 
-    if (nm_streq(sett_info->property_infos[property_idx].name, NM_SETTING_BRIDGE_VLANS)) {
+    if (property_info->param_spec == obj_properties[PROP_VLANS]) {
         if (set_b) {
             priv_a = NM_SETTING_BRIDGE_GET_PRIVATE(set_a);
             priv_b = NM_SETTING_BRIDGE_GET_PRIVATE(set_b);
@@ -1343,7 +1343,7 @@ compare_property(const NMSettInfoSetting *sett_info,
     }
 
     return NM_SETTING_CLASS(nm_setting_bridge_parent_class)
-        ->compare_property(sett_info, property_idx, con_a, set_a, con_b, set_b, flags);
+        ->compare_property(sett_info, property_info, con_a, set_a, con_b, set_b, flags);
 }
 
 /*****************************************************************************/