Add proc macro to implement models

Signed-off-by: Lee Smet <lee.smet@hotmail.com>

heromodels/heromodels-derive/tests/test_model_macro.rs

@@ -0,0 +1,31 @@
+use heromodels::model;
+use heromodels::models::core::model::{BaseModelData, Model, Index};
+
+#[model]
+struct TestUser {
+    base_data: BaseModelData,
+    
+    #[index]
+    username: String,
+    
+    #[index]
+    is_active: bool,
+}
+
+#[test]
+fn test_basic_model() {
+    assert_eq!(TestUser::db_prefix(), "test_user");
+    
+    let user = TestUser {
+        base_data: BaseModelData::new(1),
+        username: "test".to_string(),
+        is_active: true,
+    };
+    
+    let keys = user.db_keys();
+    assert_eq!(keys.len(), 2);
+    assert_eq!(keys[0].name, "username");
+    assert_eq!(keys[0].value, "test");
+    assert_eq!(keys[1].name, "is_active");
+    assert_eq!(keys[1].value, "true");
+}