bug#60623: 30.0.50; Add forward-sentence with tree sitter support

[Juri Linkov]

>>> So is this to be considered an improvement to forward-sexp too, then?
>>
>> Sorry, I can't find where a lambda is set to forward-sexp-function.
>> I only see this:
>>
>>   (defvar forward-sexp-function nil
>>
>> But if it will be set to a function later, it would be nice
>> to define a default function as well.
>
> I meant the way we did with 'transpose-sexps', where there now is a
> 'transpose-sexps-function' variable containing the factored-out earlier
> implementation.  And by if "this is an improvement" I meant declaring a
> specific defun as the default value for the defvar in question.  Maybe I
> should add the same change which is now developing here there too.
>
> What do you think?

I agree that 'transpose-sexps-function' could benefit from the same improvement.