Age out notifications

### Problem

I have a handful of applications that send constant notifications that are useful when I see them relatively quickly, but are *not* useful when they've been there for a few days. I would like to be able to set a time limit so that they are automatically dismissed.

If this is too much, is there a way to interact with the notification server via command line? I'd write a bash script to get rid of old notifications if it were the only way.

I feel that https://github.com/elementary/wingpanel-indicator-notifications/issues/217 is another solution to the same problem, but notifications sticking around for day-old chat are unimportant and I'd just prefer they just be removed.

### Proposal

Here's a beautiful mockup:

It allows a user to enter a number and then select if they want it to be treated as hours, days, etc.

### Prior Art (Optional)

_No response_