feat: add zero-arg IO.print overload and remove newline skipping in parameter parsing

Add a static `print` method with no arguments that writes only a newline, enabling blank-line output. Remove the `ignoreNewlines` calls before closing parentheses in parameter lists and method calls, tightening syntax rules. Add a `strlen` TODO comment in symbol table lookup for future optimization. Move the `Foo.toString` test from `test/io/write.wren` to `test/io/print.wren` and delete the old write test file.

builtin/io.wren

@@ -1,4 +1,8 @@
 class IO {
+  static print {
+    IO.writeString_("\n")
+  }
+
   static print(obj) {
     IO.writeString_(obj.toString)
     IO.writeString_("\n")