complete widget submodule refactory

src/browser/main/tab/page/navigation/base/mod.rs

@@ -1,9 +1,19 @@
-use gtk::Button;
+mod widget;
 
-pub fn new() -> Button {
-    Button::builder()
-        .icon_name("go-home-symbolic")
-        .tooltip_text("Base")
-        .sensitive(false)
-        .build()
+pub struct Base {
+    widget: widget::Base,
+}
+
+impl Base {
+    // Construct
+    pub fn new() -> Base {
+        Self {
+            widget: widget::Base::new(),
+        }
+    }
+
+    // Getters
+    pub fn widget(&self) -> &widget::Base {
+        &self.widget
+    }
 }