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.

test/io/print.wren

@@ -1,3 +1,10 @@
+class Foo {
+  toString { "Foo.toString" }
+}
+
+// Calls toString on argument.
+IO.print(new Foo) // expect: Foo.toString
+
 // With one argument, returns the argument.
 IO.print(IO.print(1) == 1) // expect: 1
                            // expect: true

test/io/write.wren

@@ -1,12 +0,0 @@
-class Foo {
-  toString { "Foo.toString" }
-}
-
-// Calls toString on argument.
-IO.print(new Foo) // expect: Foo.toString
-
-// Returns argument.
-var result = IO.print(123) // expect: 123
-IO.print(result == 123) // expect: true
-
-// TODO: What if toString on argument doesn't return a string?