Desktop environment customisation for Ubuntu Budgie

 Installs all Ubuntu Budgie packages, both essential dependencies
 as well as recommended packages and applications.
 Installs:
   Ubuntu Budgie panel configuration
   plank dock customisation
   gsettings overrides
   totem thumbnailer config using ffmpegthumbnailer
   Tilix integration
   ubuntu and budgie-desktop gsettings overrides
   applies the default icon-theme for GTK+ applications
   and Ubuntu Budgie plymouth branding