propertiesView: Use decoder format

Use the format that we actually used when decoding.
The mime type is usually derived from the file extension
which might not always be correct.

Issue #43

Part-of: <https://gitlab.gnome.org/Incubator/loupe/-/merge_requests/132>

src/widgets/image_view.rs

@@ -247,7 +247,7 @@ impl LpImageView {
     pub fn set_image_from_path(&self, path: &Path) {
         // Add image to recently used file. Does not work in Flatpaks:
         // <https://github.com/flatpak/xdg-desktop-portal/issues/215>
-        gtk::RecentManager::default().add_item(&dbg!(gio::File::for_path(path).uri()));
+        gtk::RecentManager::default().add_item(&gio::File::for_path(path).uri());
 
         if let Err(err) = self.load_path(path) {
             log::error!("Failed to load path: {err}");