add optional download button for unknown mime types

src/app/browser/window/tab/item/page/content/status/mime.rs

@@ -1,11 +1,31 @@
+use super::TabAction;
 use adw::StatusPage;
+use gtk::{glib::GString, prelude::ButtonExt, Align, Button};
+use std::rc::Rc;
 
 /// Create new default `GObject` preset for mime issue
 /// [StatusPage](https://gnome.pages.gitlab.gnome.org/libadwaita/doc/main/class.StatusPage.html)
-pub fn new_gobject(mime: &str) -> StatusPage {
-    StatusPage::builder()
-        .title("Oops")
+pub fn new_gobject(mime: &str, download: Option<(Rc<TabAction>, GString)>) -> StatusPage {
+    let status_page = StatusPage::builder()
         .description(format!("Content type `{mime}` not supported!"))
         .icon_name("dialog-question-symbolic")
-        .build()
+        .title("Oops")
+        .build();
+
+    if let Some((action, request)) = download {
+        let button = Button::builder()
+            .css_classes(["accent"])
+            .halign(Align::Center)
+            .label("Download")
+            .tooltip_text("Download as file to open with other application")
+            .build();
+
+        button.connect_clicked(move |_| {
+            action.load.activate(Some(request.as_str()), true);
+        });
+
+        status_page.set_child(Some(&button));
+    }
+
+    status_page
 }