Browser: Close inspectors and JS console when tab closes

Keeping these around can lead to use-after-frees and crashes.

Userland/Applications/Browser/Tab.cpp

@@ -42,6 +42,11 @@
 
 namespace Browser {
 
+Tab::~Tab()
+{
+    close_sub_widgets();
+}
+
 URL url_from_user_input(DeprecatedString const& input)
 {
     if (input.starts_with('?') && !g_search_engine.is_empty())
@@ -674,6 +679,19 @@ void Tab::show_inspector_window(Browser::Tab::InspectorTarget inspector_target)
     window->move_to_front();
 }
 
+void Tab::close_sub_widgets()
+{
+    auto close_widget_window = [](auto& widget) {
+        if (widget) {
+            auto* window = widget->window();
+            window->close();
+        }
+    };
+    close_widget_window(m_dom_inspector_widget);
+    close_widget_window(m_console_widget);
+    close_widget_window(m_storage_widget);
+}
+
 void Tab::show_console_window()
 {
     if (!m_console_widget) {

Userland/Applications/Browser/Tab.h

@@ -34,7 +34,7 @@ class Tab final : public GUI::Widget {
     friend class BrowserWindow;
 
 public:
-    virtual ~Tab() override = default;
+    virtual ~Tab() override;
 
     URL url() const;
 
@@ -106,6 +106,7 @@ private:
     void start_download(const URL& url);
     void view_source(const URL& url, DeprecatedString const& source);
     void update_status(Optional<DeprecatedString> text_override = {}, i32 count_waiting = 0);
+    void close_sub_widgets();
 
     enum class MayAppendTLD {
         No,