chore: add Clone as Trait requirement for EAV

01.workspace/heave/examples/simple_product.rs

@@ -1,7 +1,7 @@
 use heave::*;
 
 // Define a struct named `Product` to represent a product.
-#[derive(PartialEq)]
+#[derive(PartialEq, Clone)]
 struct Product {
     // `id` is a public field of type `String` to uniquely identify the product.
     pub id: String,

01.workspace/heave/examples/working_with_many_types.rs

@@ -1,27 +1,27 @@
 use heave::*;
 use std::path::Path;
 
-#[derive(PartialEq)]
+#[derive(PartialEq, Clone)]
 struct Laptop {
     pub id: String,
     pub model: String,
     pub price: u64,
 }
-#[derive(PartialEq)]
+#[derive(PartialEq, Clone)]
 struct Display {
     pub id: String,
     pub model: String,
     pub resolution: f64,
     pub price: u64,
 }
-#[derive(PartialEq)]
+#[derive(PartialEq, Clone)]
 struct Mouse {
     pub id: String,
     pub model: String,
     pub wireless: bool,
     pub price: u64,
 }
-#[derive(PartialEq)]
+#[derive(PartialEq, Clone)]
 enum Product {
     None,
     Laptop(Laptop),

01.workspace/heave/src/trt/eav.rs

@@ -8,6 +8,7 @@ pub trait T where
     Self: TryFrom<Entity>,
     Self: TryInto<Entity>,
     Self: PartialEq,
+    Self: Clone,
 {
     /// Returns the class name of the type.
     ///