Efl.Ui.Image: Add fallback when icon is not found in default theme

Summary:
If _icon_standard_set() fails, _icon_freedesktop_set() is tried.

This was causing missing icons in the homescreen example, which uses
application icons which are obviously not present in the default theme.

Thanks to @bu5hm4n!

Test Plan: The homescreen sample application from the examples repository now correctly shows all missing icons.

Reviewers: bu5hm4n, zmike

Reviewed By: zmike

Subscribers: cedric, #reviewers, #committers, bu5hm4n

Tags: #efl

Differential Revision: https://phab.enlightenment.org/D11381

src/lib/elementary/efl_ui_image.c

@@ -2151,6 +2151,11 @@ _internal_efl_ui_image_icon_set(Evas_Object *obj, const char *name, Eina_Bool *f
      {
         ret = _icon_standard_set(obj, name);
         if (ret && fdo) *fdo = EINA_FALSE;
+        if (!ret)
+          {
+             ret = _icon_freedesktop_set(obj, name, _icon_size_min_get(obj));
+             if (ret && fdo) *fdo = EINA_TRUE;
+          }
      }
    else
      {