implement generic backend methods with a macro

src/backend/macros.rs

@@ -0,0 +1,20 @@
+#[macro_export]
+macro_rules! impl_backend_constants {
+    ($name:ident) => {
+        fn get_binary(&self) -> Text {
+            BINARY
+        }
+
+        fn get_section(&self) -> Text {
+            SECTION
+        }
+
+        fn get_switches_install(&self) -> Switches {
+            SWITCHES_INSTALL
+        }
+
+        fn get_switches_remove(&self) -> Switches {
+            SWITCHES_REMOVE
+        }
+    };
+}