Feat: Add auto dark/light mode #1745

[MichelFR]

This should implement automatic dark/light mode based on
"prefers-color-scheme: dark/light"

There is an issue that should be closed if this works and gets merged:
#1745

[nurikk]

Thanks, implemented

[KameDomotics]

Thanks, implemented

Hi.
How do I set the day mode permanently? Now I always have dark mode and during the day you can't see anything. If I set the day mode, when I exit Zigbee2mqtt the next time I log in it's still night mode.
Thanks