[Bug]: Maximum zoom-in hard to see on very high resolutions

[EratoNysiad]

Version of OpenTTD

12.2

Expected result

When you're using a 1080p monitor or worse, 4x zoom-in is decent for working with.

Actual result

Newer monitors with resolutions of 4k or 8k are significantly larger, meaning 4x isn't enough anymore. I'd recommend adding 8x and 16x to this setting to facilitate playing with newer monitors:

Steps to reproduce

Open game with a 4k or 8k monitor
Sit a healthy distance away from screen
Zoom all the way in
Now you're playing the game with a resolution barely larger than 1x zoom on a 1080p monitor

[nielsmh]

Alternate would be full-screen scaling like described in #9965.