transactional-update.timer: Consider laptops and sleeping/suspended systems

[AesaraB]

Currently the systemd timer doesn't play nicely on devices that may be suspended/sleeping during the period in which the timer runs. In such cases, users may need to manually invoke transactional-update or create a new timer to ensure their system is up-to-date.

Surely there must be a more elegant solution here?

WakeSystem= exists, and may be a potential solution, but this configuration by itself does not restore the running state of the machine to the prior state