working loading and saving of files with dialog from rust

This means we are loading and saving files with the rfd crate which
utilizes platform appropriate dialogs for saving and loading files. We
can start to use this in all other file dialog locations to make sure
we are getting the right files.

It uses xdg-desktop-portals on linux so we will always use the
appropriate file dialog for each desktop environment.

src/rust/service_item_model.rs

@@ -114,6 +114,7 @@ mod service_item_model {
             // index: &'a i32,
             item: &'a QMap_QString_QVariant,
         },
+        Cleared {},
     }
 
     enum Role {
@@ -147,11 +148,13 @@ mod service_item_model {
     impl qobject::ServiceItemMod {
         #[qinvokable]
         pub fn clear(mut self: Pin<&mut Self>) {
+            println!("CLEARING ALL ITEMS");
             unsafe {
                 self.as_mut().begin_reset_model();
                 self.as_mut().service_items_mut().clear();
                 self.as_mut().end_reset_model();
             }
+            self.emit(Signals::Cleared {});
         }
 
         #[qinvokable]
@@ -734,6 +737,7 @@ mod service_item_model {
 
         #[qinvokable]
         pub fn load(mut self: Pin<&mut Self>, file: QUrl) -> bool {
+            self.as_mut().clear();
             println!("file is: {file}");
             let lfr = fs::File::open(
                 file.to_local_file().unwrap_or_default().to_string(),