Rename the OpenFile action to OpenSelectedFilename to better reflect its function (#22494)

Release Notes:

- Renamed the `OpenFile` action to `OpenSelectedFilename` for clarity

crates/gpui/src/app.rs

@@ -1226,6 +1226,11 @@ impl AppContext {
         self.actions.all_action_names()
     }
 
+    /// Get a list of all deprecated action aliases and their canonical names.
+    pub fn action_deprecations(&self) -> &[(SharedString, SharedString)] {
+        self.actions.action_deprecations()
+    }
+
     /// Register a callback to be invoked when the application is about to quit.
     /// It is not possible to cancel the quit event at this point.
     pub fn on_app_quit<Fut>(