timers: runtime-deprecate {un}enroll()

This was never a Very Good API, and generally just left so many open
ends for inconsistent behavior. The "optimization" benefit of this API
is little to none. Makes a starting step towards removing it so that in
the future timers, especially in their async_hooks interactions, can be
simplified.

PR-URL: https://github.com/nodejs/node/pull/18066


Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>