feat(video-wallpaper): Added orientation, fill mode and settings.

[spiros132]

As in the title, added the ability to change the orientation, added the ability to change the fill mode, and added a button in the context menu of the bar widget to open up the plugin settings.
@Ly-sec ready for review :)

[chenkeao]

I've already done fill mode feature and added widget setting to the context menu in #225, though I missed stretch mode. sorry, I just found out there are two plugins xD

[spiros132]

Yeah no worries xD, I found out that we could have video wallpapers with a built in component from QtMultimedia instead of using mpvpaper, so that's why I remade the mpvpaper plugin into this one to use a more "native" solution. I've tried to add the changes you made for the mpvpaper into this plugin as well, do tell me if it works out well for you or not @chenkeao :)