feat: Implement AST binder and VM

Adds a new `Binder` struct that traverses the AST and resolves variable
references to concrete `Address` types (Local, Upvalue, Global). This
information is crucial for the Virtual Machine's execution phase.

Introduces the `BoundKind` enum to represent the AST after binding.

The `VM` is updated to handle `BoundKind` nodes and execute the bound
AST.
It now manages a call stack, local variables, and closures for function
calls and upvalue capturing.

The `Environment` struct is enhanced to manage global variables and
provide
a unified interface for parsing, binding, and executing scripts. It also
includes basic standard library functions.

src/ast/compiler/mod.rs

@@ -0,0 +1,5 @@
+pub mod binder;
+pub mod bound_nodes;
+
+pub use binder::*;
+pub use bound_nodes::*;