Implement operator precedence with and without parenthesis

src/main/java/de/hsrm/compiler/Klang/ContextAnalysis.java

@@ -221,6 +221,11 @@ public class ContextAnalysis extends KlangBaseVisitor<Node> {
     return result;
   }
 
+  @Override
+  public Node visitParenthesisExpression(KlangParser.ParenthesisExpressionContext ctx) {
+    return this.visit(ctx.expression());
+  }
+
   @Override
   public Node visitEqualityExpression(KlangParser.EqualityExpressionContext ctx) {
     Node lhs = this.visit(ctx.lhs);