Use libcosmic-applet in time applet

Need to get button height right.

applets/cosmic-applet-time/src/main.rs

@@ -1,3 +1,4 @@
+use cascade::cascade;
 use gtk4::{glib, prelude::*};
 
 mod deref_cell;
@@ -7,25 +8,11 @@ use time_button::TimeButton;
 fn main() {
     gtk4::init().unwrap();
 
-    let provider = gtk4::CssProvider::new();
-    provider.load_from_data(include_bytes!("style.css"));
-    gtk4::StyleContext::add_provider_for_display(
-        &gtk4::gdk::Display::default().expect("Could not connect to a display."),
-        &provider,
-        gtk4::STYLE_PROVIDER_PRIORITY_APPLICATION,
-    );
-
-    let time_button = TimeButton::new();
-
-    gtk4::Window::builder()
-        .decorated(false)
-        .child(&time_button)
-        .resizable(false)
-        .width_request(1)
-        .height_request(1)
-        .css_classes(vec!["root_window".to_string()])
-        .build()
-        .show();
+    cascade! {
+        libcosmic_applet::AppletWindow::new();
+        ..set_child(Some(&TimeButton::new()));
+        ..show();
+    };
 
     let main_loop = glib::MainLoop::new(None, false);
     main_loop.run();