Button for the toolbar to change/cycle through Themes

[AmeJunn]

Describe the feature

I often find myself changing between my light and dark themes depending on the image, to see it in a different context. But it's really annoying to go to the settings every time to change the theme. It would be nice if there was a quick button, able to be placed on the toolbar, or via hotkey, to quickly change the theme.

How to use feature

1. Click the button / press the hotkey
2. The theme is changed

Additional context

Perhaps the themes could be marked to be changed via the button. I use 3 themes, so it's not really a on/off toggle for me for example.

But even if it's just a Dark mode/Light mode switch (like in many websites) it would still be nice. I could set the dark mode theme and the light mode theme and then just press the switch.