multi flutter ui sessions, refact 'Show displays as individual windows'

Signed-off-by: dignow <linlong1265@gmail.com>

src/ui_session_interface.rs

@@ -236,10 +236,18 @@ impl<T: InvokeUiSession> Session<T> {
         self.lc.read().unwrap().reverse_mouse_wheel.clone()
     }
 
+    pub fn get_displays_as_individual_windows(&self) -> String {
+        self.lc.read().unwrap().displays_as_individual_windows.clone()
+    }
+
     pub fn save_reverse_mouse_wheel(&self, value: String) {
         self.lc.write().unwrap().save_reverse_mouse_wheel(value);
     }
 
+    pub fn save_displays_as_individual_windows(&self, value: String) {
+        self.lc.write().unwrap().save_displays_as_individual_windows(value);
+    }
+
     pub fn save_view_style(&self, value: String) {
         self.lc.write().unwrap().save_view_style(value);
     }