Add _err_print_script_error helper methods

[Naros]

@dsnopek as discussed on RChat, here's the implementations for the "print_script_error" APIs

[dsnopek]

Thanks!

I think this should have some #ifdefs to handle the being compiled when targeting Godot 4.7 and earlier. We could maybe have the _err_print_script_error() functions fallback to print_error()?

Also, how are developers meant to call the _err_print_script_error() functions? We need a public API. If we're to match Godot's internals, this would be _err_print_error() with an ErrorHandlerType enum, but maybe it'd be better to add a nicer API to Godot for this (and then have godot-cpp match that)?