Updates for Budgie Desktop

This updates various parts of Budgie Desktop comps, such as:

- Added budgie-desktop-defaults in budgie-desktop group.
- Changed caja to nemo and added firefox in budgie-desktop-apps.
- Dropped gnome-backgrounds since we now have budgie-backgrounds.
- Dropped gnome-system-monitor from budgie-desktop group since that is more relevant to apps.
- Made budgie-desktop-view mandatory for functional desktop icons OOTB.

comps-f38.xml.in

@@ -307,8 +307,11 @@
     <default>false</default>
     <uservisible>true</uservisible>
     <packagelist>
+      <packagereq type="mandatory">budgie-backgrounds</packagereq>
       <packagereq type="mandatory">budgie-control-center</packagereq>
       <packagereq type="mandatory">budgie-desktop</packagereq>
+      <packagereq type="mandatory">budgie-desktop-defaults</packagereq>
+      <packagereq type="mandatory">budgie-desktop-view</packagereq>
       <packagereq type="mandatory">budgie-screensaver</packagereq>
       <packagereq type="mandatory">dconf</packagereq>
       <packagereq type="mandatory">gnome-settings-daemon</packagereq>
@@ -319,15 +322,12 @@
       <packagereq type="mandatory">slick-greeter</packagereq>
       <packagereq type="default">at-spi2-atk</packagereq>
       <packagereq type="default">at-spi2-core</packagereq>
-      <packagereq type="default">budgie-desktop-view</packagereq>
       <packagereq arch="aarch64,ppc64le,x86_64" type="default">fprintd-pam</packagereq>
       <packagereq type="default">glib-networking</packagereq>
-      <packagereq type="default">gnome-backgrounds</packagereq>
       <packagereq type="default">gnome-bluetooth</packagereq>
       <packagereq type="default">gnome-color-manager</packagereq>
       <packagereq type="default">gnome-disk-utility</packagereq>
       <packagereq type="default">gnome-keyring-pam</packagereq>
-      <packagereq type="default">gnome-system-monitor</packagereq>
       <packagereq arch="aarch64,ppc64le,x86_64" type="default">gvfs-afc</packagereq>
       <packagereq type="default">gvfs-afp</packagereq>
       <packagereq type="default">gvfs-archive</packagereq>
@@ -358,12 +358,13 @@
     <uservisible>true</uservisible>
     <packagelist>
       <packagereq type="default">atril</packagereq>
-      <packagereq type="default">caja</packagereq>
       <packagereq type="default">eom</packagereq>
+      <packagereq type="default">firefox</packagereq>
       <packagereq type="default">gnome-calculator</packagereq>
       <packagereq type="default">gnome-disk-utility</packagereq>
       <packagereq type="default">gnome-system-monitor</packagereq>
       <packagereq type="default">gnome-terminal</packagereq>
+      <packagereq type="default">nemo</packagereq>
       <packagereq type="default">parole</packagereq>
       <packagereq arch="aarch64,ppc64le,x86_64" type="default">rhythmbox</packagereq>
     </packagelist>