skel: xfce4-panel: replace xfce4-power-manager notification icon with battery panel plugin

- notification icon is deprecated/shows a broken icon
> https://gitlab.xfce.org/xfce/xfce4-power-manager/-/issues/104
> As a general note: if you're using the xfce4-panel don't use the trayicon. It's really the legacy option I left in to potentially enable users of other or mixed desktop environment setups to use xfce4-power-manager.

config/includes.chroot/etc/skel/.config/xfce4/panel/battery-1.rc

@@ -0,0 +1,18 @@
+display_label=false
+display_icon=true
+display_power=false
+display_percentage=false
+display_bar=false
+display_bar_time=false
+tooltip_display_percentage=true
+tooltip_display_time=true
+low_percentage=10
+critical_percentage=5
+action_on_low=1
+hide_when_full=0
+colorA=rgb(153,193,241)
+colorH=rgb(0,255,0)
+colorL=rgb(255,255,0)
+colorC=rgb(255,0,0)
+command_on_low=
+command_on_critical=

config/includes.chroot/etc/skel/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-panel.xml

@@ -16,6 +16,7 @@
         <value type="int" value="3"/>
         <value type="int" value="15"/>
         <value type="int" value="6"/>
+        <value type="int" value="1"/>
         <value type="int" value="7"/>
         <value type="int" value="5"/>
         <value type="int" value="4"/>
@@ -64,5 +65,6 @@
       </property>
     </property>
     <property name="plugin-2" type="string" value="whiskermenu"/>
-  </property>
+    <property name="plugin-1" type="string" value="battery"/>
+  </property>1
 </channel>

config/includes.chroot/etc/skel/.config/xfce4/xfconf/xfce-perchannel-xml/xfce4-power-manager.xml

@@ -16,6 +16,6 @@
     <property name="dpms-on-ac-off" type="uint" value="12"/>
     <property name="inactivity-sleep-mode-on-battery" type="uint" value="1"/>
     <property name="inactivity-on-battery" type="uint" value="15"/>
-    <property name="show-tray-icon" type="int" value="1"/>
+    <property name="show-tray-icon" type="bool" value="false"/>
   </property>
 </channel>