The "\>" delimeter is not rendering correctly

I'm using the c# port of stringtemplate 4.0.6.9004.

Per the [cheatsheet](https://github.com/antlr/stringtemplate4/blob/master/doc/cheatsheet.md), stringtemplate4 is supposed to recognize `\<` and `\>` as escaped characters `<` and `>`. Escaping `\<` works properly but `\>` does not.

This template worked correctly in stringtemplate3 but in upgrading to stringtemplate4, we see that the string `"\<\>"` rendering yields `"<\>"`.

Start with the escaping behavior described in the cheatsheet and reproduce the template containing the escaped less-than and greater-than characters in the C# port. Done means the template renders both escaped characters correctly, matching the documented behavior and the StringTemplate 3 result.

Written by the indexing model from the issue text.