servoshell: Migrate to egui-file-dialog from tinyfiledialogs (#34823)

This is the first step toward completely replacing tinyfiledialogs with
an egui-based solution.

Signed-off-by: L Ashwin B <lashwinib@gmail.com>

components/net/tests/filemanager_thread.rs

@@ -49,7 +49,7 @@ fn test_filemanager() {
             patterns.clone(),
             tx,
             origin.clone(),
-            Some("tests/test.jpeg".to_string()),
+            Some("tests/test.jpeg".into()),
         ));
         let selected = rx
             .recv()