BaseView: Set minimum width to 360

While the HomeView and ShowView can't yet scale that low,
the ShowWidget could get to about 270p already which is not
desirable.

This commit sets the minimum width of all the Views to 360p,
which is our mobile target size.

podcasts-gtk/src/widgets/base_view.rs

@@ -13,6 +13,7 @@ impl Default for BaseView {
         let scrolled_window = gtk::ScrolledWindow::new(None, None);
 
         scrolled_window.set_policy(PolicyType::Never, PolicyType::Automatic);
+        container.set_size_request(360, -1);
         container.add(&scrolled_window);
         container.show_all();