BrowserSettings: Add a tab to control the Browser's autoplay settings

This adds a checkbox to enable autoplay on all websites (disabled by
default) and a website list to enable autoplay on individual websites
(set to file:// URLs only by default).

Userland/Applications/BrowserSettings/AutoplaySettingsWidget.gml

@@ -0,0 +1,35 @@
+@GUI::Frame {
+    fill_with_background_color: true
+    layout: @GUI::VerticalBoxLayout {
+        margins: [8]
+    }
+
+    @GUI::CheckBox {
+        name: "allow_autoplay_on_all_websites_checkbox"
+        text: "Allow media to automatically play on all websites"
+    }
+
+    @GUI::GroupBox {
+        title: "Autoplay Allowlist"
+        layout: @GUI::VerticalBoxLayout {
+            margins: [8]
+        }
+
+        @GUI::ListView {
+            name: "allowlist_view"
+        }
+
+        @GUI::Widget {
+            fixed_height: 32
+            layout: @GUI::HorizontalBoxLayout {}
+
+            @GUI::Layout::Spacer {}
+
+            @GUI::Button {
+                name: "add_website_button"
+                fixed_width: 100
+                text: "Add website..."
+            }
+        }
+    }
+}