Change the behaviour of the Comment Poll

[viktorsmari]

Problem: All comments are polled every 3 seconds from the /api/. They are always re-rendered, no matter what.

• This is annoying if you are reading a comment that can be scrolled sideways.
• This is annoying if you are trying to select / highlight text, in order to copy it.

Screenshot:

Video: https://imgur.com/a/5pAs3oK

How to reproduce: Try reading the first comment and scroll it sideways. https://x.piratar.is/polity/1/issue/408/ Try highlighting any text in comment and wait 2-3 seconds.

Possible solutions: Only re-render comments that have changed, or are new.