[Idea] add pacdiff and scheduled paccache cleanup script to CachyOS Hello

Hi there dear Cachy team,

I was thinking how about adding two additional features for the CachyOS Hello window under Apps/Tweaks menu:

- `cachy-pacdiff` with `meld` DIFFPROG implementation, so that users can routinely check and review any lingering pacnew/pacsave files.
- `cachy-paccache-service` which would allow the users to customize in a GUI a cleaning period (daily,weekly or monthly) and the number of the latest package versions to keep (which is an input field of any interger value over 0), and then it would run the service in the background as a systemd timer, technically running **paccache -rk**_N_ where N is the number of versions to keep the user previously inputted.