declare wrapper types with macro

src/cp437_grid.rs

@@ -1,19 +1,9 @@
 use crate::char_grid::CharGrid;
 use servicepoint::{DataRef, Grid};
-use std::sync::{Arc, RwLock};
+use std::sync::{Arc};
+use crate::macros::wrap_uniffi_object;
 
-#[derive(uniffi::Object)]
-pub struct Cp437Grid {
-    pub(crate) actual: RwLock<servicepoint::Cp437Grid>,
-}
-
-impl Cp437Grid {
-    pub(crate) fn internal_new(actual: servicepoint::Cp437Grid) -> Arc<Self> {
-        Arc::new(Self {
-            actual: RwLock::new(actual),
-        })
-    }
-}
+wrap_uniffi_object!(Cp437Grid);
 
 #[uniffi::export]
 impl Cp437Grid {