move migration api out of struct implementation

src/app/browser/window/tab/item/page/navigation/request.rs

@@ -117,18 +117,18 @@ impl Request {
             _ => None,
         }
     }
-
-    // Tools
-    pub fn migrate(tx: &Transaction) -> Result<(), String> {
-        // Migrate self components
-        if let Err(e) = Database::init(tx) {
-            return Err(e.to_string());
-        }
-
-        // Delegate migration to childs
-        Widget::migrate(tx)?;
-
-        // Success
-        Ok(())
-    }
+}
+
+// Tools
+pub fn migrate(tx: &Transaction) -> Result<(), String> {
+    // Migrate self components
+    if let Err(e) = Database::init(tx) {
+        return Err(e.to_string());
+    }
+
+    // Delegate migration to childs
+    widget::migrate(tx)?;
+
+    // Success
+    Ok(())
 }