Add condition-case success handler (bug#47677)

Add condition-case success handler (bug#47677)

Allow a condition-case handler on the form (:success BODY) to be
specified as the success continuation of the protected form, with
the specified variable bound to its result.

* src/eval.c (Fcondition_case): Update the doc string.
(internal_lisp_condition_case): Implement in interpreter.
(syms_of_eval): Defsym :success.
* lisp/emacs-lisp/bytecomp.el (byte-compile-condition-case):
Implement in byte-compiler.
* lisp/emacs-lisp/cl-macs.el (cl--self-tco): Allow self-TCO
from success handler.
* doc/lispref/control.texi (Handling Errors): Update manual.
* etc/NEWS: Announce.
* test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-tests--test-cases)
(bytecomp-condition-case-success):
* test/lisp/emacs-lisp/cl-macs-tests.el (cl-macs--labels):
Add test cases.