Complete Antergos NeXT custom theme with cross-DE support

- Custom GTK3/GTK4/GTK2 theme (AntergosNeXT) with blue #2EA3F2 accent
- KDE Plasma color scheme matching the theme
- dconf overrides for GNOME/Cinnamon/Budgie/Deepin
- XFCE xfconf defaults for theme/icon/font
- GTK settings.ini for all GTK-based DEs
- /etc/skel defaults for new users

packages/antergos-next-desktop-settings/xsettings.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<channel name="xsettings" version="1.0">
+  <property name="Net" type="empty">
+    <property name="ThemeName" type="string" value="Breeze-Dark"/>
+    <property name="IconThemeName" type="string" value="breeze-dark"/>
+  </property>
+  <property name="Gtk" type="empty">
+    <property name="CursorThemeName" type="string" value="breeze_cursors"/>
+    <property name="FontName" type="string" value="Noto Sans, 10"/>
+  </property>
+</channel>