Add forward-sentence with tree sitter support (bug#60623)

Add forward-sentence with tree sitter support (bug#60623)

* etc/NEWS: Mention the new changes.
* lisp/textmodes/paragraphs.el (forward-sentence-default-function):
Move old implementation to its own function.
(forward-sentence-function): New defvar defaulting to old behavior.
(forward-sentence): Use the variable in this function unconditionally.
* lisp/treesit.el (treesit-sentence-type-regexp): New defvar.
(treesit-forward-sentence): New defun.
(treesit-major-mode-setup): Conditionally set
forward-sentence-function.
* doc/emacs/programs.texi (Defuns): Add new subsection.
(Moving by Sentences): Add some documentation with xrefs to the elisp
manual and related nodes.
* doc/lispref/positions.texi (List Motion): Mention
treesit-sentence-type-regexp and describe how to enable this
functionality.