👷 window: refactor creation into struct module

Author: vnepogodin

src/data_types.rs

@@ -1,11 +1,3 @@
-#[derive(Clone, Debug)]
-#[repr(C)]
-pub struct HelloWindow {
-    pub builder: gtk::Builder,
-    pub window: gtk::Window,
-    pub preferences: serde_json::Value,
-}
-
 #[derive(Clone, Debug)]
 #[repr(C)]
 pub struct SystemdUnits {