Use a few more hook functions also in top-level buffers

Use a few more hook functions also in top-level buffers

* sweeprolog.el (sweeprolog-top-level-mode): Set
'forward-sexp-function', 'beginning-of-defun-function',
'end-of-defun-function' and 'syntax-propertize-function' hooks to
their Prolog-specific value that we already use in 'sweeprolog-mode'.