examples: fix libcosmic features, warnings, etc.

examples/calendar/Cargo.toml

@@ -10,5 +10,4 @@ chrono = "0.4.40"
 
 [dependencies.libcosmic]
 path = "../../"
-default-features = false
 features = ["debug", "winit", "tokio", "xdg-portal", "wgpu"]

examples/calendar/src/main.rs

@@ -113,6 +113,9 @@ where
 {
     fn update_title(&mut self) -> cosmic::app::Task<Message> {
         self.set_header_title(String::from("Calendar Demo"));
-        self.set_window_title(String::from("Calendar Demo"))
+        self.set_window_title(
+            String::from("Calendar Demo"),
+            self.core.main_window_id().unwrap(),
+        )
     }
 }