CC Mode: Remove annoying background fontification. Should fix bug #52298

CC Mode: Remove annoying background fontification.  Should fix bug #52298

Partially revert the commits from 2021-10-24 - 2021-10-26, "CC Mode: Fontify
"found types" which are recognized after being first scanned".

This removes the background fontification which ran off of a 0.1s timer, but
leaves the facility of normal fontification causing the fontification
throughout the buffer of newly found types.

* lisp/progmodes/cc-fonts.el (c-find-types-background)
(c-type-finder-timer-func): Remove.

* lisp/progmodes/cc-mode.el (c-type-finder-timer, c-inhibit-type-finder)
(c-type-finder-pos, c-post-gc-hook): Remove.
(c-leave-cc-mode-mode): Remove the manipulations of c-type-finder-timer and
c-post-gc-hook.
(c-basic-common-init): Remove the manipulations of c-type-finder-pos,
c-type-finder-timer, and c-post-gc-hook.

* lisp/progmodes/cc-vars.el (c-type-finder-time-slot)
(c-type-finder-repeat-time, c-type-finder-chunk-size): Remove.

* doc/misc/cc-mode.texi (Found Types): Remove.  Amend some menu entries.