New `sort` keyword arguments (bug#69709)

New `sort` keyword arguments (bug#69709)

Add the :key, :lessp, :reverse and :in-place keyword arguments.
The old calling style remains available and is unchanged.

* src/fns.c (sort_list, sort_vector, Fsort):
* src/sort.c (tim_sort):
Add keyword arguments with associated new features.
All callers of Fsort adapted.
* test/src/fns-tests.el (fns-tests--shuffle-vector, fns-tests-sort-kw):
New test.
* doc/lispref/sequences.texi (Sequence Functions): Update manual.
* etc/NEWS: Announce.