Refactor Value enum for Quote node

Replaces `Value::Object(Rc<dyn Object>)` for SyntaxNodes with a
dedicated `Value::Quote(Rc<SyntaxNode>)`. This provides better type
safety and clarity when dealing with AST nodes as values.
Refactor Value enum for Quote node

This commit introduces a new `Value::Quote` variant to represent quoted
AST nodes directly, replacing the generic `Value::Object` for this
purpose.

This change simplifies the handling of quoted nodes by:
- Directly storing an `Rc<SyntaxNode>` instead of relying on dynamic
  downcasting from `Rc<dyn Object>`.
- Streamlining macro expansion logic by removing the need to check for
  `SyntaxNode` within `Value::Object`.
- Improving type safety and explicitness in the `Value` enum.

src/ast/environment.rs

@@ -22,7 +22,7 @@ use crate::ast::compiler::optimizer::Optimizer;
 use crate::ast::compiler::specializer::{FunctionRegistry, MonoCache, Specializer};
 use crate::ast::rtl::{self, intrinsics};
 use crate::ast::types::{
-    NativeFunction, NodeIdentity, Object, Purity, SourceLocation, StaticType, Value,
+    NativeFunction, NodeIdentity, Purity, SourceLocation, StaticType, Value,
 };
 
 use crate::ast::diagnostics::{DiagnosticLevel, Diagnostics};
@@ -121,7 +121,7 @@ impl MacroEvaluator for RuntimeMacroEvaluator {
         if let SyntaxKind::Identifier { symbol: sym, .. } = &node.kind
             && let Some(arg_node) = bindings.get(&sym.name)
         {
-            return Ok(Value::Object(Rc::new(arg_node.clone()) as Rc<dyn Object>));
+            return Ok(Value::Quote(Rc::new(arg_node.clone())));
         }
 
         let mut diag = Diagnostics::new();