Use proper faces in apropos.el.

Use proper faces in apropos.el.

* lisp/apropos.el (apropos-symbol, apropos-keybinding, apropos-label)
(apropos-property, apropos-function-button)
(apropos-variable-button, apropos-misc-button): New faces.
(apropos-symbol-face, apropos-keybinding-face)
(apropos-label-face, apropos-property-face, apropos-match-face):
Variables removed.
(apropos-library-button, apropos-format-plist, apropos-print)
(apropos-print-doc, apropos-describe-plist): Callers changed.

Fixes: debbugs:8396