Always show a wallpaper to the main display

[AkazaRenn]

Is your feature request related to a problem? Please describe.
When the main display changes (like display connection/disconnection, or simply changed in settings), we need to re-apply the wallpaper to the new main display.

Describe the solution you'd like
Hook on Windows display settings change and check if the main display has been changed, if yes, move the wallpaper accordingly. And it will be provided as a togglable option.

Describe alternatives you've considered
I cannot find a alternative.

Additional context
I was told the wallpapers are bond by display ID, so I tried assigning the same wallpaper to the two possible main displays I usually use (external display no. 1 and internal display), but I found it not working very well, as the wallpaper ended up on external display no. 2 somehow. And having to manually set it for every possible main display is somewhat troublesome.