refactor(Value): add Symbol.toStringTag() and tag getter.

Author: sciborrudnicki

src/lib/value.class.ts

@@ -6,6 +6,16 @@
  * @template Type 
  */
 export abstract class Value<Type> {
+  /**
+   * @description Returns the `string` tag representation of the `Value` class when used in `Object.prototype.toString.call(instance)`.
+   * @public
+   * @readonly
+   * @type {string}
+   */
+  public get [Symbol.toStringTag]() {
+    return 'Value';
+  }
+
   /**
    * @description Returns the privately stored value of generic type variable `Type`.
    * @public
@@ -32,6 +42,16 @@ export abstract class Value<Type> {
     this.#value = value;
   }
 
+  /**
+   * @description Extracts the string tag of the current instance defined by the `Symbol.toStringTag`.
+   * @public
+   * @returns {string | undefined} The extracted class name, such as `'Value'`, or `undefined` if extraction fails.
+   */
+  public get tag(): string | undefined {
+    const tag = Object.prototype.toString.call(this).slice(8, -1);
+    return tag !== 'Object' ? tag : undefined;
+  }
+
   /**
    * @description Sets the value of generic type variable `Type`.
    * @protected