feat(error): add custom error handling aliases

src/model/mod.rs

@@ -5,6 +5,9 @@ use crate::gtk::glib;
 
 use glib::Object;
 
+pub type Result<T> = core::result::Result<T, Error>;
+pub type Error = std::boxed::Box<dyn std::error::Error>;
+
 glib::wrapper! {
     pub struct Frequency(ObjectSubclass<models::Frequency>);
 }