Implement translate_location for error highlighting on templates

[eileencodes]

Hello!

@tenderlove and I recently implemented the ability for error highlight to highlight the errors in templates. (see ruby/error_highlight#26, ruby/ruby#6703, rails/rails#46171, and finally rails/rails#46908).

In order for haml to get the underlining on template errors, translate_location needs to be implemented. I've added a deprecation warning to Rails so that other templating engines will see this (but I wanted to open an issue for you as well).

The translate location from Rails is defined here and called from here.

Let me know if I can clarify anything.