Add mqtt_uns_structure configuration and uninstall functionality (#196)

- Prompt user for mqtt_uns_structure during installation and update src/config.py accordingly.
- Implement uninstall function in remote_install.sh to remove the rpi-mqtt-monitor directory, cron job, and systemd service.
- Update rpi-cpu2mqtt.py to utilize mqtt_uns_structure for state topics, ensuring proper MQTT topic structure.
- Modify config.py.example to include mqtt_uns_structure with a default empty value.

Co-authored-by: Sam Blackman <sam@samuelblackman.com>

remote_install.sh

@@ -22,6 +22,46 @@ welcome(){
   fi	
 }
 
+uninstall(){
+  printm "Uninstalling rpi-mqtt-monitor"
+  
+  # Remove the rpi-mqtt-monitor directory
+  if [ -d "rpi-mqtt-monitor" ]; then
+    rm -rf rpi-mqtt-monitor
+    echo "Removed rpi-mqtt-monitor directory."
+  else
+    echo "rpi-mqtt-monitor directory not found."
+  fi
+
+  # Remove the cron job if it exists
+  if crontab -l | grep -q rpi-cpu2mqtt.py; then
+    crontab -l | grep -v rpi-cpu2mqtt.py | crontab -
+    echo "Removed cron job for rpi-cpu2mqtt.py."
+  else
+    echo "No cron job found for rpi-cpu2mqtt.py."
+  fi
+
+  # Remove the systemd service if it exists
+  if [ -f /etc/systemd/system/rpi-mqtt-monitor.service ]; then
+    sudo systemctl stop rpi-mqtt-monitor.service
+    sudo systemctl disable rpi-mqtt-monitor.service
+    sudo rm /etc/systemd/system/rpi-mqtt-monitor.service
+    sudo systemctl daemon-reload
+    echo "Removed systemd service for rpi-mqtt-monitor."
+  else
+    echo "No systemd service found for rpi-mqtt-monitor."
+  fi
+
+  # Optionally remove git if it was installed by this script
+  if command -v git &> /dev/null; then
+    read -r -p "Do you want to remove git? [y/N] " response
+    if [[ "$response" =~ ^([yY][eE][sS]|[yY])$ ]]; then
+      sudo apt-get remove --purge git
+      echo "Git has been removed."
+    fi
+  fi
+}
+
 main(){
   welcome
   if [[ $(git --version)  ]]; then 
@@ -37,4 +77,9 @@ main(){
   bash install.sh
 }
 
-main
+# Check for uninstall flag
+if [[ "$1" == "uninstall" ]]; then
+  uninstall
+else
+  main
+fi