Multiple pagination templates should be one

Summary

There are three main different pagination templates used throughout the Queue. Two named pagination.html, one in templates/, one in templates/request/list/ and one of the two is copy pasted entirely into participants.html.

I suggest we use one of these everywhere instead of using three different ones.

Reasoning

Fixing a bug in one of the three does not - in any way, shape or form - guarantee the bug is solved everywhere...