src: add incr/decr operators for Reference

This commit adds operator overloads for increment/decrement to
AliasedBuffer::Reference.
The motivation for doing this is to hopefully make code that needs
to increment/decrement a little simpler.

PR-URL: https://github.com/nodejs/node/pull/19083


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Tiancheng "Timothy" Gu <timothygu99@gmail.com>