feat(ast): Implement toString method for Object class and update ExprImpl

Author: GeekMasher

ql/lib/codeql/bicep/ast/Resources.qll

@@ -51,6 +51,8 @@ class Object extends Expr instanceof ObjectImpl {
       result = property.getValue()
     )
   }
+
+  override string toString() { result = "Object" }
 }
 
 /**

ql/lib/codeql/bicep/ast/internal/Expr.qll

@@ -8,4 +8,6 @@ private import Stmts
  */
 class ExprImpl extends StmtsImpl, TExpr {
   override string getAPrimaryQlClass() { result = "Expr" }
+
+  override string toString() { none() } 
 }

ql/lib/codeql/bicep/ast/internal/Object.qll

@@ -19,7 +19,7 @@ class ObjectImpl extends TObject, AstNode {
 
   ObjectImpl() { this = TObject(ast) }
 
-  override string toString() { result = ast.toString() }
+  // override string toString() { result = ast.toString() }
 
   ObjectPropertyImpl getProperty(int index) { toTreeSitter(result) = ast.getChild(index) }