Dismiss all button is too aggressive

[christianlupus]

Steps to reproduce

1. Ensure you have more notifications than visible on one page
2. Click the dismiss all button

Expected behaviour

I can see the next page of notifications.

Actual behaviour

All notifications are dismissed and no longer visible.

This is a problem especially if there might be important notifications on the "later" pages present but these I cannot preview or see at all. So this is a button I highly avoid clicking having to dismiss the notifications one by one.

[nickvergessen]

I think we kind of need both.
We have some people that misconfigured notification (or for most its activity) and end up with thousands of notifications. We can not make them click them away in 25-sized batches (Ref #1741)